Zeckendorf arithmetic

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Task
Zeckendorf arithmetic
You are encouraged to solve this task according to the task description, using any language you may know.

This task is a total immersion zeckendorf task; using decimal numbers will attract serious disapprobation.

The task is to implement addition, subtraction, multiplication, and division using Zeckendorf number representation. Optionally provide decrement, increment and comparitive operation functions.

Addition

Like binary 1 + 1 = 10, note carry 1 left. There the similarity ends. 10 + 10 = 101, note carry 1 left and 1 right. 100 + 100 = 1001, note carry 1 left and 2 right, this is the general case.

Occurrences of 11 must be changed to 100. Occurrences of 111 may be changed from the right by replacing 11 with 100, or from the left converting 111 to 100 + 100;

Subtraction

10 - 1 = 1. The general rule is borrow 1 right carry 1 left. eg:

  abcde
  10100 -
   1000
  _____
    100  borrow 1 from a leaves 100
  + 100  add the carry
  _____
   1001

A larger example:

  abcdef
  100100 -
    1000
  ______
  1*0100 borrow 1 from b
   + 100 add the carry
  ______
  1*1001

Sadly we borrowed 1 from b which didn't have it to lend. So now b borrows from a:

    1001
  + 1000 add the carry
    ____
   10100
Multiplication

Here you teach your computer its zeckendorf tables. eg. 101 * 1001:

  a = 1 * 101 = 101
  b = 10 * 101 = a + a = 10000
  c = 100 * 101 = b + a = 10101
  d = 1000 * 101 = c + b = 101010

  1001 = d + a therefore 101 * 1001 =
 
  101010
   + 101
  ______
 1000100
Division

Lets try 1000101 divided by 101, so we can use the same table used for multiplication.

  1000101 -
   101010 subtract d (1000 * 101)
  _______
     1000 -
      101 b and c are too large to subtract, so subtract a
     ____
        1 so 1000101 divided by 101 is d + a (1001) remainder 1

Efficient algorithms for Zeckendorf arithmetic is interesting. The sections on addition and subtraction are particularly relevant for this task.

C

Translation of: D

<lang c>#include <stdbool.h>

  1. include <stdio.h>
  2. include <string.h>

int inv(int a) {

   return a ^ -1;

}

struct Zeckendorf {

   int dVal, dLen;

};

void a(struct Zeckendorf *self, int n) {

   void b(struct Zeckendorf *, int); // forward declare
   int i = n;
   while (true) {
       if (self->dLen < i) self->dLen = i;
       int j = (self->dVal >> (i * 2)) & 3;
       switch (j) {
       case 0:
       case 1:
           return;
       case 2:
           if (((self->dVal >> ((i + 1) * 2)) & 1) != 1) return;
           self->dVal += 1 << (i * 2 + 1);
           return;
       case 3:
           self->dVal = self->dVal & inv(3 << (i * 2));
           b(self, (i + 1) * 2);
           break;
       default:
           break;
       }
       i++;
   }

}

void b(struct Zeckendorf *self, int pos) {

   void increment(struct Zeckendorf *); // forward declare
   if (pos == 0) {
       increment(self);
       return;
   }
   if (((self->dVal >> pos) & 1) == 0) {
       self->dVal += 1 << pos;
       a(self, pos / 2);
       if (pos > 1) a(self, pos / 2 - 1);
   } else {
       self->dVal = self->dVal & inv(1 << pos);
       b(self, pos + 1);
       b(self, pos - (pos > 1 ? 2 : 1));
   }

}

void c(struct Zeckendorf *self, int pos) {

   if (((self->dVal >> pos) & 1) == 1) {
       self->dVal = self->dVal & inv(1 << pos);
       return;
   }
   c(self, pos + 1);
   if (pos > 0) {
       b(self, pos - 1);
   } else {
       increment(self);
   }

}

struct Zeckendorf makeZeckendorf(char *x) {

   struct Zeckendorf z = { 0, 0 };
   int i = strlen(x) - 1;
   int q = 1;
   z.dLen = i / 2;
   while (i >= 0) {
       z.dVal += (x[i] - '0') * q;
       q *= 2;
       i--;
   }
   return z;

}

void increment(struct Zeckendorf *self) {

   self->dVal++;
   a(self, 0);

}

void addAssign(struct Zeckendorf *self, struct Zeckendorf rhs) {

   int gn;
   for (gn = 0; gn < (rhs.dLen + 1) * 2; gn++) {
       if (((rhs.dVal >> gn) & 1) == 1) {
           b(self, gn);
       }
   }

}

void subAssign(struct Zeckendorf *self, struct Zeckendorf rhs) {

   int gn;
   for (gn = 0; gn < (rhs.dLen + 1) * 2; gn++) {
       if (((rhs.dVal >> gn) & 1) == 1) {
           c(self, gn);
       }
   }
   while ((((self->dVal >> self->dLen * 2) & 3) == 0) || (self->dLen == 0)) {
       self->dLen--;
   }

}

void mulAssign(struct Zeckendorf *self, struct Zeckendorf rhs) {

   struct Zeckendorf na = rhs;
   struct Zeckendorf nb = rhs;
   struct Zeckendorf nr = makeZeckendorf("0");
   struct Zeckendorf nt;
   int i;
   for (i = 0; i < (self->dLen + 1) * 2; i++) {
       if (((self->dVal >> i) & 1) > 0) addAssign(&nr, nb);
       nt = nb;
       addAssign(&nb, na);
       na = nt;
   }
   *self = nr;

}

void printZeckendorf(struct Zeckendorf z) {

   static const char *const dig[3] = { "00", "01", "10" };
   static const char *const dig1[3] = { "", "1", "10" };
   if (z.dVal == 0) {
       printf("0");
       return;
   } else {
       int idx = (z.dVal >> (z.dLen * 2)) & 3;
       int i;
       printf(dig1[idx]);
       for (i = z.dLen - 1; i >= 0; i--) {
           idx = (z.dVal >> (i * 2)) & 3;
           printf(dig[idx]);
       }
   }

}

int main() {

   struct Zeckendorf g;
   printf("Addition:\n");
   g = makeZeckendorf("10");
   addAssign(&g, makeZeckendorf("10"));
   printZeckendorf(g);
   printf("\n");
   addAssign(&g, makeZeckendorf("10"));
   printZeckendorf(g);
   printf("\n");
   addAssign(&g, makeZeckendorf("1001"));
   printZeckendorf(g);
   printf("\n");
   addAssign(&g, makeZeckendorf("1000"));
   printZeckendorf(g);
   printf("\n");
   addAssign(&g, makeZeckendorf("10101"));
   printZeckendorf(g);
   printf("\n\n");
   printf("Subtraction:\n");
   g = makeZeckendorf("1000");
   subAssign(&g, makeZeckendorf("101"));
   printZeckendorf(g);
   printf("\n");
   g = makeZeckendorf("10101010");
   subAssign(&g, makeZeckendorf("1010101"));
   printZeckendorf(g);
   printf("\n\n");
   printf("Multiplication:\n");
   g = makeZeckendorf("1001");
   mulAssign(&g, makeZeckendorf("101"));
   printZeckendorf(g);
   printf("\n");
   g = makeZeckendorf("101010");
   addAssign(&g, makeZeckendorf("101"));
   printZeckendorf(g);
   printf("\n");
   return 0;

}</lang>

Output:
Addition:
101
1001
10101
100101
1010000

Subtraction:
1
1000000

Multiplication:
1000100
1000100

C#

Translation of: Java

<lang csharp>using System; using System.Text;

namespace ZeckendorfArithmetic {

   class Zeckendorf : IComparable<Zeckendorf> {
       private static readonly string[] dig = { "00", "01", "10" };
       private static readonly string[] dig1 = { "", "1", "10" };
       private int dVal = 0;
       private int dLen = 0;
       public Zeckendorf() : this("0") {
           // empty
       }
       public Zeckendorf(string x) {
           int q = 1;
           int i = x.Length - 1;
           dLen = i / 2;
           while (i >= 0) {
               dVal += (x[i] - '0') * q;
               q *= 2;
               i--;
           }
       }
       private void A(int n) {
           int i = n;
           while (true) {
               if (dLen < i) dLen = i;
               int j = (dVal >> (i * 2)) & 3;
               switch (j) {
                   case 0:
                   case 1:
                       return;
                   case 2:
                       if (((dVal >> ((i + 1) * 2)) & 1) != 1) return;
                       dVal += 1 << (i * 2 + 1);
                       return;
                   case 3:
                       int temp = 3 << (i * 2);
                       temp ^= -1;
                       dVal = dVal & temp;
                       B((i + 1) * 2);
                       break;
               }
               i++;
           }
       }
       private void B(int pos) {
           if (pos == 0) {
               Inc();
               return;
           }
           if (((dVal >> pos) & 1) == 0) {
               dVal += 1 << pos;
               A(pos / 2);
               if (pos > 1) A(pos / 2 - 1);
           }
           else {
               int temp = 1 << pos;
               temp ^= -1;
               dVal = dVal & temp;
               B(pos + 1);
               B(pos - (pos > 1 ? 2 : 1));
           }
       }
       private void C(int pos) {
           if (((dVal >> pos) & 1) == 1) {
               int temp = 1 << pos;
               temp ^= -1;
               dVal = dVal & temp;
               return;
           }
           C(pos + 1);
           if (pos > 0) {
               B(pos - 1);
           }
           else {
               Inc();
           }
       }
       public Zeckendorf Inc() {
           dVal++;
           A(0);
           return this;
       }
       public Zeckendorf Copy() {
           Zeckendorf z = new Zeckendorf {
               dVal = dVal,
               dLen = dLen
           };
           return z;
       }
       public void PlusAssign(Zeckendorf other) {
           for (int gn = 0; gn < (other.dLen + 1) * 2; gn++) {
               if (((other.dVal >> gn) & 1) == 1) {
                   B(gn);
               }
           }
       }
       public void MinusAssign(Zeckendorf other) {
           for (int gn = 0; gn < (other.dLen + 1) * 2; gn++) {
               if (((other.dVal >> gn) & 1) == 1) {
                   C(gn);
               }
           }
           while ((((dVal >> dLen * 2) & 3) == 0) || (dLen == 0)) {
               dLen--;
           }
       }
       public void TimesAssign(Zeckendorf other) {
           Zeckendorf na = other.Copy();
           Zeckendorf nb = other.Copy();
           Zeckendorf nt;
           Zeckendorf nr = new Zeckendorf();
           for (int i = 0; i < (dLen + 1) * 2; i++) {
               if (((dVal >> i) & 1) > 0) {
                   nr.PlusAssign(nb);
               }
               nt = nb.Copy();
               nb.PlusAssign(na);
               na = nt.Copy();
           }
           dVal = nr.dVal;
           dLen = nr.dLen;
       }
       public int CompareTo(Zeckendorf other) {
           return dVal.CompareTo(other.dVal);
       }
       public override string ToString() {
           if (dVal == 0) {
               return "0";
           }
           int idx = (dVal >> (dLen * 2)) & 3;
           StringBuilder sb = new StringBuilder(dig1[idx]);
           for (int i = dLen - 1; i >= 0; i--) {
               idx = (dVal >> (i * 2)) & 3;
               sb.Append(dig[idx]);
           }
           return sb.ToString();
       }
   }
   class Program {
       static void Main(string[] args) {
           Console.WriteLine("Addition:");
           Zeckendorf g = new Zeckendorf("10");
           g.PlusAssign(new Zeckendorf("10"));
           Console.WriteLine(g);
           g.PlusAssign(new Zeckendorf("10"));
           Console.WriteLine(g);
           g.PlusAssign(new Zeckendorf("1001"));
           Console.WriteLine(g);
           g.PlusAssign(new Zeckendorf("1000"));
           Console.WriteLine(g);
           g.PlusAssign(new Zeckendorf("10101"));
           Console.WriteLine(g);
           Console.WriteLine();
           Console.WriteLine("Subtraction:");
           g = new Zeckendorf("1000");
           g.MinusAssign(new Zeckendorf("101"));
           Console.WriteLine(g);
           g = new Zeckendorf("10101010");
           g.MinusAssign(new Zeckendorf("1010101"));
           Console.WriteLine(g);
           Console.WriteLine();
           Console.WriteLine("Multiplication:");
           g = new Zeckendorf("1001");
           g.TimesAssign(new Zeckendorf("101"));
           Console.WriteLine(g);
           g = new Zeckendorf("101010");
           g.PlusAssign(new Zeckendorf("101"));
           Console.WriteLine(g);
       }
   }

}</lang>

Output:
Addition:
101
1001
10101
100101
1010000

Subtraction:
1
1000000

Multiplication:
1000100
1000100

C++

Works with: C++11

<lang cpp>// For a class N which implements Zeckendorf numbers: // I define an increment operation ++() // I define a comparison operation <=(other N) // I define an addition operation +=(other N) // I define a subtraction operation -=(other N) // Nigel Galloway October 28th., 2012

  1. include <iostream>

enum class zd {N00,N01,N10,N11}; class N { private:

 int dVal = 0, dLen;
 void _a(int i) {
   for (;; i++) {
     if (dLen < i) dLen = i;
     switch ((zd)((dVal >> (i*2)) & 3)) {
       case zd::N00: case zd::N01: return;
       case zd::N10: if (((dVal >> ((i+1)*2)) & 1) != 1) return;
                     dVal += (1 << (i*2+1)); return;
       case zd::N11: dVal &= ~(3 << (i*2)); _b((i+1)*2);
 }}}
 void _b(int pos) {
   if (pos == 0) {++*this; return;}
   if (((dVal >> pos) & 1) == 0) {
     dVal += 1 << pos;
     _a(pos/2);
     if (pos > 1) _a((pos/2)-1);
     } else {
     dVal &= ~(1 << pos);
     _b(pos + 1);
     _b(pos - ((pos > 1)? 2:1));
 }}
 void _c(int pos) {
   if (((dVal >> pos) & 1) == 1) {dVal &= ~(1 << pos); return;}
   _c(pos + 1);
   if (pos > 0) _b(pos - 1); else ++*this;
   return;
 }

public:

 N(char const* x = "0") {
   int i = 0, q = 1;
   for (; x[i] > 0; i++);
   for (dLen = --i/2; i >= 0; i--) {dVal+=(x[i]-48)*q; q*=2;
 }}
 const N& operator++() {dVal += 1; _a(0); return *this;}
 const N& operator+=(const N& other) {
   for (int GN = 0; GN < (other.dLen + 1) * 2; GN++) if ((other.dVal >> GN) & 1 == 1) _b(GN);
   return *this;
 }
 const N& operator-=(const N& other) {
   for (int GN = 0; GN < (other.dLen + 1) * 2; GN++) if ((other.dVal >> GN) & 1 == 1) _c(GN);
   for (;((dVal >> dLen*2) & 3) == 0 or dLen == 0; dLen--);
   return *this;
 }
 const N& operator*=(const N& other) {
   N Na = other, Nb = other, Nt, Nr;
   for (int i = 0; i <= (dLen + 1) * 2; i++) {
     if (((dVal >> i) & 1) > 0) Nr += Nb;
     Nt = Nb; Nb += Na; Na = Nt;
   }
   return *this = Nr;
 }
 const bool operator<=(const N& other) const {return dVal <= other.dVal;}
 friend std::ostream& operator<<(std::ostream&, const N&);

}; N operator "" N(char const* x) {return N(x);} std::ostream &operator<<(std::ostream &os, const N &G) {

 const static std::string dig[] {"00","01","10"}, dig1[] {"","1","10"};
 if (G.dVal == 0) return os << "0";
 os << dig1[(G.dVal >> (G.dLen*2)) & 3];
 for (int i = G.dLen-1; i >= 0; i--) os << dig[(G.dVal >> (i*2)) & 3];
 return os;

} </lang>

Testing

The following tests addtition: <lang cpp>int main(void) {

 N G;
 G = 10N;
 G += 10N;
 std::cout << G << std::endl;
 G += 10N;
 std::cout << G << std::endl;
 G += 1001N;
 std::cout << G << std::endl;
 G += 1000N;
 std::cout << G << std::endl;
 G += 10101N;
 std::cout << G << std::endl;
 return 0;

}</lang>

Output:
101
1001
10101
100101
1010000

The following tests subtraction: <lang cpp>int main(void) {

 N G;
 G = 1000N;
 G -= 101N;
 std::cout << G << std::endl;
 G = 10101010N;
 G -= 1010101N;
 std::cout << G << std::endl;
 return 0;

}</lang>

Output:
1
1000000

The following tests multiplication: <lang cpp> int main(void) {

 N G = 1001N;
 G *= 101N;
 std::cout << G << std::endl;
 G = 101010N;
 G += 101N;
 std::cout << G << std::endl;
 return 0;

}</lang>

Output:
1000100
1000100

D

Translation of: Kotlin

<lang D>import std.stdio;

int inv(int a) {

   return a ^ -1;

}

class Zeckendorf {

   private int dVal;
   private int dLen;
   private void a(int n) {
       auto i = n;
       while (true) {
           if (dLen < i) dLen = i;
           auto j = (dVal >> (i * 2)) & 3;
           switch(j) {
               case 0:
               case 1:
                   return;
               case 2:
                   if (((dVal >> ((i + 1) * 2)) & 1) != 1) return;
                   dVal += 1 << (i * 2 + 1);
                   return;
               case 3:
                   dVal = dVal & (3 << (i * 2)).inv();
                   b((i + 1) * 2);
                   break;
               default:
                   assert(false);
           }
           i++;
       }
   }
   private void b(int pos) {
       if (pos == 0) {
           this++;
           return;
       }
       if (((dVal >> pos) & 1) == 0) {
           dVal += 1 << pos;
           a(pos / 2);
           if (pos > 1) a(pos / 2 - 1);
       } else {
           dVal = dVal & (1 << pos).inv();
           b(pos + 1);
           b(pos - (pos > 1 ? 2 : 1));
       }
   }
   private void c(int pos) {
       if (((dVal >> pos) & 1) == 1) {
           dVal = dVal & (1 << pos).inv();
           return;
       }
       c(pos + 1);
       if (pos > 0) {
           b(pos - 1);
       } else {
           ++this;
       }
   }
   this(string x = "0") {
       int q = 1;
       int i = x.length - 1;
       dLen = i / 2;
       while (i >= 0) {
           dVal += (x[i] - '0') * q;
           q *= 2;
           i--;
       }
   }
   auto opUnary(string op : "++")() {
       dVal += 1;
       a(0);
       return this;
   }
   void opOpAssign(string op : "+")(Zeckendorf rhs) {
       foreach (gn; 0..(rhs.dLen + 1) * 2) {
           if (((rhs.dVal >> gn) & 1) == 1) {
               b(gn);
           }
       }
   }
   void opOpAssign(string op : "-")(Zeckendorf rhs) {
       foreach (gn; 0..(rhs.dLen + 1) * 2) {
           if (((rhs.dVal >> gn) & 1) == 1) {
               c(gn);
           }
       }
       while ((((dVal >> dLen * 2) & 3) == 0) || (dLen == 0)) {
           dLen--;
       }
   }
   void opOpAssign(string op : "*")(Zeckendorf rhs) {
       auto na = rhs.dup;
       auto nb = rhs.dup;
       Zeckendorf nt;
       auto nr = "0".Z;
       foreach (i; 0..(dLen + 1) * 2) {
           if (((dVal >> i) & 1) > 0) nr += nb;
           nt = nb.dup;
           nb += na;
           na = nt.dup;
       }
       dVal = nr.dVal;
       dLen = nr.dLen;
   }
   void toString(scope void delegate(const(char)[]) sink) const {
       if (dVal == 0) {
           sink("0");
           return;
       }
       sink(dig1[(dVal >> (dLen * 2)) & 3]);
       foreach_reverse (i; 0..dLen) {
           sink(dig[(dVal >> (i * 2)) & 3]);
       }
   }
   Zeckendorf dup() {
       auto z = "0".Z;
       z.dVal = dVal;
       z.dLen = dLen;
       return z;
   }
   enum dig = ["00", "01", "10"];
   enum dig1 = ["", "1", "10"];

}

auto Z(string val) {

   return new Zeckendorf(val);

}

void main() {

   writeln("Addition:");
   auto g = "10".Z;
   g += "10".Z;
   writeln(g);
   g += "10".Z;
   writeln(g);
   g += "1001".Z;
   writeln(g);
   g += "1000".Z;
   writeln(g);
   g += "10101".Z;
   writeln(g);
   writeln();
   writeln("Subtraction:");
   g = "1000".Z;
   g -= "101".Z;
   writeln(g);
   g = "10101010".Z;
   g -= "1010101".Z;
   writeln(g);
   writeln();
   writeln("Multiplication:");
   g = "1001".Z;
   g *= "101".Z;
   writeln(g);
   g = "101010".Z;
   g += "101".Z;
   writeln(g);

}</lang>

Output:
Addition:
101
1001
10101
100101
1010000

Subtraction:
1
1000000

Multiplication:
1000100
1000100

Elena

Translation of: C++

ELENA 5.0 : <lang elena>import extensions;

const dig = new string[]{"00","01","10"}; const dig1 = new string[]{"","1","10"};

sealed struct ZeckendorfNumber {

   int dVal;
   int dLen;
   
   clone()
       = ZeckendorfNumber.newInternal(dVal,dLen);
   
   cast n(string s)
   {
       int i := s.Length - 1;
       int q := 1;
       
       dLen := i / 2;
       dVal := 0;
       
       while (i >= 0)
       {
           dVal += ((intConvertor.convert(s[i]) - 48) * q);
           q *= 2;
           
           i -= 1
       }
   }
   
   internal readContent(ref int val, ref int len)
   {
       val := dVal;
       len := dLen;
   }
   
   private a(int n)
   {
       int i := n;
       while (true)
       {
           if (dLen < i)
           {
               dLen := i
           };
           
           int v := (dVal $shr (i * 2)) && 3;
           v =>    
               0 { ^ self }
               1 { ^ self }
               2 {
                   ifnot ((dVal $shr ((i + 1) * 2)).allMask:1)
                   {
                       ^ self
                   };
                   
                   dVal += (1 $shl (i*2 + 1));
                   
                   ^ self
               }
               3 {
                   int tmp := 3 $shl (i * 2);
                   tmp := tmp.xor(-1);
                   dVal := dVal && tmp;
                   
                   self.b((i+1)*2)
               };
           
           i += 1
       }
   }
   
   inc()
   {
       dVal += 1;
       self.a(0)
   }
   
   private b(int pos)
   {
       if (pos == 0) { ^ self.inc() };
       
       ifnot((dVal $shr pos).allMask:1)
       {
           dVal += (1 $shl pos);
           self.a(pos / 2);
           if (pos > 1) { self.a((pos / 2) - 1) }
       }
       else
       {
           dVal := dVal && (1 $shl pos).Inverted;
           self.b(pos + 1);
           int arg := pos - ((pos > 1) ? 2 : 1);
           self.b(/*pos - ((pos > 1) ? 2 : 1)*/arg)
       }
   }
   private c(int pos)
   {
       if ((dVal $shr pos).allMask:1)
       {
           int tmp := 1 $shl pos;
           tmp := tmp.xor(-1);
           
           dVal := dVal && tmp;
           
           ^ self
       };
                                       
       self.c(pos + 1);
       
       if (pos > 0)
       {
           self.b(pos - 1)
       }
       else
       {
           self.inc()
       }            
   }
           
   internal constructor sum(ZeckendorfNumber n, ZeckendorfNumber m)
   {
       int mVal := 0;
       int mLen := 0;
       
       n.readContent(ref dVal, ref dLen);        
       m.readContent(ref mVal, ref mLen);
       
       for(int GN := 0, GN < (mLen + 1) * 2, GN += 1)
       {
           if ((mVal $shr GN).allMask:1)
           {
               self.b(GN)
           }
       }
   }
   
   internal constructor difference(ZeckendorfNumber n, ZeckendorfNumber m)
   {
       int mVal := 0;
       int mLen := 0;
       
       n.readContent(ref dVal, ref dLen);        
       m.readContent(ref mVal, ref mLen);
       
       for(int GN := 0, GN < (mLen + 1) * 2, GN += 1) 
       {
           if ((mVal $shr GN).allMask:1)
           {
               self.c(GN)
           }
       };
       
       while (((dVal $shr (dLen*2)) && 3) == 0 || dLen == 0)
       {
           dLen -= 1
       }
   }
   
   internal constructor product(ZeckendorfNumber n, ZeckendorfNumber m)
   {
       n.readContent(ref dVal, ref dLen);              
       
       ZeckendorfNumber Na := m;
       ZeckendorfNumber Nb := m;
       ZeckendorfNumber Nr := 0n;
       ZeckendorfNumber Nt := 0n;
       
       for(int i := 0, i < (dLen + 1) * 2, i += 1) 
       {
           if (((dVal $shr i) && 1) > 0)
           {
               Nr += Nb
           };
           Nt := Nb;
           Nb += Na;
           Na := Nt
       };
       
       Nr.readContent(ref dVal, ref dLen);
   }
   
   internal constructor newInternal(int v, int l)
   {
       dVal := v;
       dLen := l
   }
   
   string toPrintable()
   {
       if (dVal == 0)
           { ^ "0" };
           
       string s := dig1[(dVal $shr (dLen * 2)) && 3];
       int i := dLen - 1;
       while (i >= 0)
       {
           s := s + dig[(dVal $shr (i * 2)) && 3];
           
           i-=1
       };
       
       ^ s
   }
   
   add(ZeckendorfNumber n)
       = ZeckendorfNumber.sum(self, n);
       
   subtract(ZeckendorfNumber n)
       = ZeckendorfNumber.difference(self, n);
       
   multiply(ZeckendorfNumber n)
       = ZeckendorfNumber.product(self, n);

}

public program() {

   console.printLine("Addition:");
   var n := 10n;
   
   n += 10n;
   console.printLine(n);
   n += 10n;
   console.printLine(n);
   n += 1001n;
   console.printLine(n);
   n += 1000n;
   console.printLine(n);
   n += 10101n;
   console.printLine(n);
   
   console.printLine("Subtraction:");
   n := 1000n;
   n -= 101n;
   console.printLine(n);
   n := 10101010n;
   n -= 1010101n;
   console.printLine(n);
   
   console.printLine("Multiplication:");
   n := 1001n;
   n *= 101n;
   console.printLine(n);
   n := 101010n;
   n += 101n;
   console.printLine(n)

}</lang>

Output:
Addition:
101
1001
10101
100101
1010000
Subtraction:
1
1000000
Multiplication:
1000100
1000100

Go

Translation of: Kotlin

<lang go>package main

import (

   "fmt"
   "strings"

)

var (

   dig  = [3]string{"00", "01", "10"}
   dig1 = [3]string{"", "1", "10"}

)

type Zeckendorf struct{ dVal, dLen int }

func NewZeck(x string) *Zeckendorf {

   z := new(Zeckendorf)
   if x == "" {
       x = "0"
   }
   q := 1
   i := len(x) - 1
   z.dLen = i / 2
   for ; i >= 0; i-- {
       z.dVal += int(x[i]-'0') * q
       q *= 2
   }
   return z

}

func (z *Zeckendorf) a(i int) {

   for ; ; i++ {
       if z.dLen < i {
           z.dLen = i
       }
       j := (z.dVal >> uint(i*2)) & 3
       switch j {
       case 0, 1:
           return
       case 2:
           if ((z.dVal >> (uint(i+1) * 2)) & 1) != 1 {
               return
           }
           z.dVal += 1 << uint(i*2+1)
           return
       case 3:
           z.dVal &= ^(3 << uint(i*2))
           z.b((i + 1) * 2)
       }
   }

}

func (z *Zeckendorf) b(pos int) {

   if pos == 0 {
       z.Inc()
       return
   }
   if ((z.dVal >> uint(pos)) & 1) == 0 {
       z.dVal += 1 << uint(pos)
       z.a(pos / 2)
       if pos > 1 {
           z.a(pos/2 - 1)
       }
   } else {
       z.dVal &= ^(1 << uint(pos))
       z.b(pos + 1)
       temp := 1
       if pos > 1 {
           temp = 2
       }
       z.b(pos - temp)
   }

}

func (z *Zeckendorf) c(pos int) {

   if ((z.dVal >> uint(pos)) & 1) == 1 {
       z.dVal &= ^(1 << uint(pos))
       return
   }
   z.c(pos + 1)
   if pos > 0 {
       z.b(pos - 1)
   } else {
       z.Inc()
   }

}

func (z *Zeckendorf) Inc() {

   z.dVal++
   z.a(0)

}

func (z1 *Zeckendorf) PlusAssign(z2 *Zeckendorf) {

   for gn := 0; gn < (z2.dLen+1)*2; gn++ {
       if ((z2.dVal >> uint(gn)) & 1) == 1 {
           z1.b(gn)
       }
   }

}

func (z1 *Zeckendorf) MinusAssign(z2 *Zeckendorf) {

   for gn := 0; gn < (z2.dLen+1)*2; gn++ {
       if ((z2.dVal >> uint(gn)) & 1) == 1 {
           z1.c(gn)
       }
   }
   for z1.dLen > 0 && ((z1.dVal>>uint(z1.dLen*2))&3) == 0 {
       z1.dLen--
   }

}

func (z1 *Zeckendorf) TimesAssign(z2 *Zeckendorf) {

   na := z2.Copy()
   nb := z2.Copy()
   nr := new(Zeckendorf)
   for i := 0; i <= (z1.dLen+1)*2; i++ {
       if ((z1.dVal >> uint(i)) & 1) > 0 {
           nr.PlusAssign(nb)
       }
       nt := nb.Copy()
       nb.PlusAssign(na)
       na = nt.Copy()
   }
   z1.dVal = nr.dVal
   z1.dLen = nr.dLen

}

func (z *Zeckendorf) Copy() *Zeckendorf {

   return &Zeckendorf{z.dVal, z.dLen}

}

func (z1 *Zeckendorf) Compare(z2 *Zeckendorf) int {

   switch {
   case z1.dVal < z2.dVal:
       return -1
   case z1.dVal > z2.dVal:
       return 1
   default:
       return 0
   }

}

func (z *Zeckendorf) String() string {

   if z.dVal == 0 {
       return "0"
   }
   var sb strings.Builder
   sb.WriteString(dig1[(z.dVal>>uint(z.dLen*2))&3])
   for i := z.dLen - 1; i >= 0; i-- {
       sb.WriteString(dig[(z.dVal>>uint(i*2))&3])
   }
   return sb.String()

}

func main() {

   fmt.Println("Addition:")
   g := NewZeck("10")
   g.PlusAssign(NewZeck("10"))
   fmt.Println(g)
   g.PlusAssign(NewZeck("10"))
   fmt.Println(g)
   g.PlusAssign(NewZeck("1001"))
   fmt.Println(g)
   g.PlusAssign(NewZeck("1000"))
   fmt.Println(g)
   g.PlusAssign(NewZeck("10101"))
   fmt.Println(g)
   fmt.Println("\nSubtraction:")
   g = NewZeck("1000")
   g.MinusAssign(NewZeck("101"))
   fmt.Println(g)
   g = NewZeck("10101010")
   g.MinusAssign(NewZeck("1010101"))
   fmt.Println(g)
   fmt.Println("\nMultiplication:")
   g = NewZeck("1001")
   g.TimesAssign(NewZeck("101"))
   fmt.Println(g)
   g = NewZeck("101010")
   g.PlusAssign(NewZeck("101"))
   fmt.Println(g)

}</lang>

Output:
Addition:
101
1001
10101
100101
1010000

Subtraction:
1
1000000

Multiplication:
1000100
1000100

Java

Translation of: Kotlin
Works with: Java version 9

<lang Java>import java.util.List;

public class Zeckendorf implements Comparable<Zeckendorf> {

   private static List<String> dig = List.of("00", "01", "10");
   private static List<String> dig1 = List.of("", "1", "10");
   private String x;
   private int dVal = 0;
   private int dLen = 0;
   public Zeckendorf() {
       this("0");
   }
   public Zeckendorf(String x) {
       this.x = x;
       int q = 1;
       int i = x.length() - 1;
       dLen = i / 2;
       while (i >= 0) {
           dVal += (x.charAt(i) - '0') * q;
           q *= 2;
           i--;
       }
   }
   private void a(int n) {
       int i = n;
       while (true) {
           if (dLen < i) dLen = i;
           int j = (dVal >> (i * 2)) & 3;
           switch (j) {
               case 0:
               case 1:
                   return;
               case 2:
                   if (((dVal >> ((i + 1) * 2)) & 1) != 1) return;
                   dVal += 1 << (i * 2 + 1);
                   return;
               case 3:
                   int temp = 3 << (i * 2);
                   temp ^= -1;
                   dVal = dVal & temp;
                   b((i + 1) * 2);
                   break;
           }
           i++;
       }
   }
   private void b(int pos) {
       if (pos == 0) {
           Zeckendorf thiz = this;
           thiz.inc();
           return;
       }
       if (((dVal >> pos) & 1) == 0) {
           dVal += 1 << pos;
           a(pos / 2);
           if (pos > 1) a(pos / 2 - 1);
       } else {
           int temp = 1 << pos;
           temp ^= -1;
           dVal = dVal & temp;
           b(pos + 1);
           b(pos - (pos > 1 ? 2 : 1));
       }
   }
   private void c(int pos) {
       if (((dVal >> pos) & 1) == 1) {
           int temp = 1 << pos;
           temp ^= -1;
           dVal = dVal & temp;
           return;
       }
       c(pos + 1);
       if (pos > 0) {
           b(pos - 1);
       } else {
           Zeckendorf thiz = this;
           thiz.inc();
       }
   }
   public Zeckendorf inc() {
       dVal++;
       a(0);
       return this;
   }
   public void plusAssign(Zeckendorf other) {
       for (int gn = 0; gn < (other.dLen + 1) * 2; gn++) {
           if (((other.dVal >> gn) & 1) == 1) {
               b(gn);
           }
       }
   }
   public void minusAssign(Zeckendorf other) {
       for (int gn = 0; gn < (other.dLen + 1) * 2; gn++) {
           if (((other.dVal >> gn) & 1) == 1) {
               c(gn);
           }
       }
       while ((((dVal >> dLen * 2) & 3) == 0) || (dLen == 0)) {
           dLen--;
       }
   }
   public void timesAssign(Zeckendorf other) {
       Zeckendorf na = other.copy();
       Zeckendorf nb = other.copy();
       Zeckendorf nt;
       Zeckendorf nr = new Zeckendorf();
       for (int i = 0; i < (dLen + 1) * 2; i++) {
           if (((dVal >> i) & 1) > 0) {
               nr.plusAssign(nb);
           }
           nt = nb.copy();
           nb.plusAssign(na);
           na = nt.copy();
       }
       dVal = nr.dVal;
       dLen = nr.dLen;
   }
   private Zeckendorf copy() {
       Zeckendorf z = new Zeckendorf();
       z.dVal = dVal;
       z.dLen = dLen;
       return z;
   }
   @Override
   public int compareTo(Zeckendorf other) {
       return ((Integer) dVal).compareTo(other.dVal);
   }
   @Override
   public String toString() {
       if (dVal == 0) {
           return "0";
       }
       int idx = (dVal >> (dLen * 2)) & 3;
       StringBuilder stringBuilder = new StringBuilder(dig1.get(idx));
       for (int i = dLen - 1; i >= 0; i--) {
           idx = (dVal >> (i * 2)) & 3;
           stringBuilder.append(dig.get(idx));
       }
       return stringBuilder.toString();
   }
   public static void main(String[] args) {
       System.out.println("Addition:");
       Zeckendorf g = new Zeckendorf("10");
       g.plusAssign(new Zeckendorf("10"));
       System.out.println(g);
       g.plusAssign(new Zeckendorf("10"));
       System.out.println(g);
       g.plusAssign(new Zeckendorf("1001"));
       System.out.println(g);
       g.plusAssign(new Zeckendorf("1000"));
       System.out.println(g);
       g.plusAssign(new Zeckendorf("10101"));
       System.out.println(g);
       System.out.println("\nSubtraction:");
       g = new Zeckendorf("1000");
       g.minusAssign(new Zeckendorf("101"));
       System.out.println(g);
       g = new Zeckendorf("10101010");
       g.minusAssign(new Zeckendorf("1010101"));
       System.out.println(g);
       System.out.println("\nMultiplication:");
       g = new Zeckendorf("1001");
       g.timesAssign(new Zeckendorf("101"));
       System.out.println(g);
       g = new Zeckendorf("101010");
       g.plusAssign(new Zeckendorf("101"));
       System.out.println(g);
   }

}</lang>

Output:
Addition:
101
1001
10101
100101
1010000

Subtraction:
1
1000000

Multiplication:
1000100
1000100

Julia

Influenced by the format of the Tcl and Perl 6 versions, but added other functionality. <lang julia>import Base.*, Base.+, Base.-, Base./, Base.show, Base.!=, Base.==, Base.<=, Base.<, Base.>, Base.>=, Base.divrem

const z0 = "0" const z1 = "1" const flipordered = (z1 < z0)

mutable struct Z s::String end Z() = Z(z0) Z(z::Z) = Z(z.s)

pairlen(x::Z, y::Z) = max(length(x.s), length(y.s)) tolen(x::Z, n::Int) = (s = x.s; while length(s) < n s = z0 * s end; s)

<(x::Z, y::Z) = (l = pairlen(x, y); flipordered ? tolen(x, l) > tolen(y, l) : tolen(x, l) < tolen(y, l)) >(x::Z, y::Z) = (l = pairlen(x, y); flipordered ? tolen(x, l) < tolen(y, l) : tolen(x, l) > tolen(y, l)) ==(x::Z, y::Z) = (l = pairlen(x, y); tolen(x, l) == tolen(y, l)) <=(x::Z, y::Z) = (l = pairlen(x, y); flipordered ? tolen(x, l) >= tolen(y, l) : tolen(x, l) <= tolen(y, l)) >=(x::Z, y::Z) = (l = pairlen(x, y); flipordered ? tolen(x, l) <= tolen(y, l) : tolen(x, l) >= tolen(y, l)) !=(x::Z, y::Z) = (l = pairlen(x, y); tolen(x, l) != tolen(y, l))

function tocanonical(z::Z)

   while occursin(z0 * z1 * z1, z.s)
       z.s = replace(z.s, z0 * z1 * z1 => z1 * z0 * z0)
   end
   len = length(z.s)
   if len > 1 && z.s[1:2] == z1 * z1
       z.s = z1 * z0 * z0 * ((len > 2) ? z.s[3:end] : "")
   end
   while (len = length(z.s)) > 1 && string(z.s[1]) == z0
       if len == 2
           if z.s == z0 * z0
               z.s = z0
           elseif z.s == z0 * z1
               z.s = z1
           end
       else
           z.s = z.s[2:end]
       end
   end
   z

end

function inc(z)

   if z.s[end] == z0[1]
       z.s = z.s[1:end-1] * z1[1]
   elseif z.s[end] == z1[1]
       if length(z.s) > 1
           if z.s[end-1:end] == z0 * z1
               z.s = z.s[1:end-2] * z1 * z0
           end
       else
           z.s = z1 * z0
       end
   end
   tocanonical(z)

end

function dec(z)

   if z.s[end] == z1[1]
       z.s = z.s[1:end-1] * z0
   else
       if (m = match(Regex(z1 * z0 * '+' * '$'), z.s)) != nothing
           len = length(m.match)
           if iseven(len)
               z.s = z.s[1:end-len] * (z0 * z1) ^ div(len, 2)
           else
               z.s = z.s[1:end-len] * (z0 * z1) ^ div(len, 2) * z0
           end
       end
   end
   tocanonical(z)    
   z

end

function +(x::Z, y::Z)

   a = Z(x.s)
   b = Z(y.s)
   while b.s != z0
       inc(a)
       dec(b)
   end
   a

end

function -(x::Z, y::Z)

   a = Z(x.s)
   b = Z(y.s)
   while b.s != z0
       dec(a)
       dec(b)
   end
   a

end

function *(x::Z, y::Z)

   if (x.s == z0) || (y.s == z0)
       return Z(z0)
   elseif x.s == z1
       return Z(y.s)
   elseif y.s == z1
       return Z(x.s)
   end
   a = Z(x.s)
   b = Z(z1)
   while b != y
       c = Z(z0)
       while c != x
           inc(a)
           inc(c)
       end
       inc(b)
   end
   a

end

function divrem(x::Z, y::Z)

   if y.s == z0
       throw("Zeckendorf division by 0")
   elseif (y.s == z1) || (x.s == z0)
       return Z(x.s)
   end
   a = Z(x.s)
   b = Z(y.s)
   c = Z(z0)
   while a > b
       a = a - b
       inc(c)
   end
   tocanonical(c), tocanonical(a)

end

function /(x::Z, y::Z)

   a, _ = divrem(x, y)
   a

end

show(io::IO, z::Z) = show(io, parse(BigInt, tocanonical(z).s))

function zeckendorftest()

   a = Z("10")
   b = Z("1001")
   c = Z("1000")
   d = Z("10101")
   println("Addition:")
   x = a
   println(x += a)
   println(x += a)
   println(x += b)
   println(x += c)
   println(x += d)
   println("\nSubtraction:")
   x = Z("1000")
   println(x - Z("101"))
   x = Z("10101010")
   println(x - Z("1010101"))
   println("\nMultiplication:")
   x = Z("1001")
   y = Z("101")
   println(x * y)
   println(Z("101010") * y)
   println("\nDivision:")
   x = Z("1000101")
   y = Z("101")
   println(x / y)
   println(divrem(x, y))

end

zeckendorftest()

</lang>

Output:

Addition:
101
1001
10101
100101
1010000 

Subtraction:
1
1000000

Multiplication:
1000100
101000101

Division:
1001
(1001, 1)

Kotlin

Translation of: C++

<lang scala>// version 1.1.51

class Zeckendorf(x: String = "0") : Comparable<Zeckendorf> {

   var dVal = 0
   var dLen = 0
   private fun a(n: Int) {
       var i = n
       while (true) {
           if (dLen < i) dLen = i
           val j = (dVal shr (i * 2)) and 3
           when (j) {
               0, 1 -> return
               2 -> {
                   if (((dVal shr ((i + 1) * 2)) and 1) != 1) return
                   dVal += 1 shl (i * 2 + 1)
                   return
               }
               3 -> {
                   dVal = dVal and (3 shl (i * 2)).inv()
                   b((i + 1) * 2)
               }
           }
           i++
       }
   }
   private fun b(pos: Int) {
       if (pos == 0) {
           var thiz = this
           ++thiz
           return
       }
       if (((dVal shr pos) and 1) == 0) {
           dVal += 1 shl pos
           a(pos / 2)
           if (pos > 1) a(pos / 2 - 1)
       }
       else {
           dVal = dVal and (1 shl pos).inv()
           b(pos + 1)
           b(pos - (if (pos > 1) 2 else 1))
       }
   }
   private fun c(pos: Int) {
       if (((dVal shr pos) and 1) == 1) {
           dVal = dVal and (1 shl pos).inv()
           return
       }
       c(pos + 1)
       if (pos > 0) b(pos - 1) else { var thiz = this; ++thiz }
   }
   init {
       var q = 1
       var i = x.length - 1
       dLen = i / 2
       while (i >= 0) {
           dVal += (x[i] - '0').toInt() * q
           q *= 2
           i--
       }
   }
   operator fun inc(): Zeckendorf {
       dVal += 1
       a(0)
       return this
   }
   operator fun plusAssign(other: Zeckendorf) {
       for (gn in 0 until (other.dLen + 1) * 2) {
           if (((other.dVal shr gn) and 1) == 1) b(gn)
       }
   }
   operator fun minusAssign(other: Zeckendorf) {
       for (gn in 0 until (other.dLen + 1) * 2) {
           if (((other.dVal shr gn) and 1) == 1) c(gn)
       }
       while ((((dVal shr dLen * 2) and 3) == 0) || (dLen == 0)) dLen--
   }
   operator fun timesAssign(other: Zeckendorf) {
       var na = other.copy()
       var nb = other.copy()
       var nt: Zeckendorf
       var nr = "0".Z
       for (i in 0..(dLen + 1) * 2) {
           if (((dVal shr i) and 1) > 0) nr += nb
           nt = nb.copy()
           nb += na
           na = nt.copy()
       }
       dVal = nr.dVal
       dLen = nr.dLen
   }
   override operator fun compareTo(other: Zeckendorf) = dVal.compareTo(other.dVal)
   override fun toString(): String {
       if (dVal == 0) return "0"
       val sb = StringBuilder(dig1[(dVal shr (dLen * 2)) and 3])
       for (i in dLen - 1 downTo 0) {
           sb.append(dig[(dVal shr (i * 2)) and 3])
       }
       return sb.toString()
   }
   fun copy(): Zeckendorf {
       val z = "0".Z
       z.dVal = dVal
       z.dLen = dLen
       return z
   }
   companion object {
       val dig = listOf("00", "01", "10")
       val dig1 = listOf("", "1", "10")
   }

}

val String.Z get() = Zeckendorf(this)

fun main(args: Array<String>) {

   println("Addition:")
   var g = "10".Z
   g += "10".Z
   println(g)
   g += "10".Z
   println(g)
   g += "1001".Z
   println(g)
   g += "1000".Z
   println(g)
   g += "10101".Z
   println(g)
   println("\nSubtraction:")
   g = "1000".Z
   g -= "101".Z
   println(g)
   g = "10101010".Z
   g -= "1010101".Z
   println(g)
   println("\nMultiplication:")
   g = "1001".Z
   g *= "101".Z
   println(g)
   g = "101010".Z
   g += "101".Z
   println(g)

}</lang>

Output:
Addition:
101
1001
10101
100101
1010000

Subtraction:
1
1000000

Multiplication:
1000100
1000100

Phix

Uses a binary representation of Zeckendorf numbers, eg decimal 11 is stored as 0b10100, ie meaning 8+3, but actually 20 in decimal.
As such, they can be directly compared using the standard comparison operators, and printed quite trivially just by using the %b format.
They are however (and not all that surprisingly) pulled apart into individual bits for addition/subtraction, etc.
Does not handle negative numbers or anything >139583862445 (-ve probably doable but messy, >1.4e12 requires a total rewrite, probably using string representation). <lang Phix>sequence fib = {1,1}

function zeckendorf(atom n) -- Same as Zeckendorf_number_representation#Phix atom r = 0

   while fib[$]<n do
       fib &= fib[$] + fib[$-1]
   end while
   integer k = length(fib)
   while k>2 and n<fib[k] do
       k -= 1
   end while   
   for i=k to 2 by -1 do
       integer c = n>=fib[i]
       r += r+c
       n -= c*fib[i]
   end for
   return r

end function

function decimal(object z) -- Convert Zeckendorf number(s) to decimal atom dec = 0, bit = 2

   if sequence(z) then
       for i=1 to length(z) do
           z[i] = decimal(z[i])
       end for
       return z
   end if
   while z do
       if and_bits(z,1) then
           dec += fib[bit]
       end if
       bit += 1
       if bit>length(fib) then
           fib &= fib[$] + fib[$-1]
       end if
       z = floor(z/2)
   end while
   return dec

end function

function to_bits(integer x) -- Simplified copy of int_to_bits(), but in reverse order, -- and +ve only but (also only) as many bits as needed, and -- ensures there are *two* trailing 0 (most significant)

   sequence bits = {}
   if x<0 then ?9/0 end if     -- sanity/avoid infinite loop
   while 1 do
       bits &= remainder(x,2)
       if x=0 then exit end if
       x = floor(x/2)
   end while
   bits &= 0 -- (since eg 101+101 -> 10000)
   return bits

end function

function to_bits2(integer a,b) -- Apply to_bits() to a and b, and pad to the same length

   sequence sa = to_bits(a), sb = to_bits(b)
   integer diff = length(sa)-length(sb)
   if diff!=0 then
       if diff<0 then  sa &= repeat(0,-diff)
                 else  sb &= repeat(0,+diff)
       end if
   end if
   return {sa,sb}

end function

function to_int(sequence bits) -- Copy of bits_to_int(), but in reverse order (lsb last)

   atom val = 0, p = 1
   for i=length(bits) to 1 by -1 do
       if bits[i] then
           val += p
       end if
       p += p
   end for
   return val

end function

function zstr(object z)

   if sequence(z) then
       for i=1 to length(z) do
           z[i] = zstr(z[i])
       end for
       return z
   end if
   return sprintf("%b",z)

end function

function rep(sequence res, integer ds, sequence was, wth) -- helper for cleanup, validates replacements

   integer de = ds+length(was)-1
   if res[ds..de]!=was then ?9/0 end if
   if length(was)!=length(wth) then ?9/0 end if
   res[ds..de] = wth
   return res

end function

function zcleanup(sequence res) -- (shared by zadd and zsub)

   integer l = length(res)
   -- first stage, left to right, {020x -> 100x', 030x -> 110x', 021x->110x, 012x->101x}
   for i=1 to l-3 do
       switch res[i..i+2]
           case {0,2,0}:   res[i..i+2] = {1,0,0}   res[i+3] += 1
           case {0,3,0}:   res[i..i+2] = {1,1,0}   res[i+3] += 1
           case {0,2,1}:   res[i..i+2] = {1,1,0}
           case {0,1,2}:   res[i..i+2] = {1,0,1}
       end switch
   end for
   -- first stage cleanup
   if l>1 then
       if res[l-1]=3 then      res = rep(res,l-2,{0,3,0},{1,1,1})      -- 030 -> 111
       elsif res[l-1]=2 then
           if res[l-2]=0 then  res = rep(res,l-2,{0,2,0},{1,0,1})      -- 020 -> 101
                         else  res = rep(res,l-3,{0,1,2,0},{1,0,1,0})  -- 0120 -> 1010
           end if
       end if
   end if
   if res[l]=3 then            res = rep(res,l-1,{0,3},{1,1})          -- 03 -> 11
   elsif res[l]=2 then
       if res[l-1]=0 then      res = rep(res,l-1,{0,2},{1,0})          -- 02 -> 10
                     else      res = rep(res,l-2,{0,1,2},{1,0,1})      -- 012 -> 101
       end if
   end if      
   -- second stage, pass 1, right to left, 011 -> 100
   for i=length(res)-2 to 1 by -1 do
       if res[i..i+2]={0,1,1} then res[i..i+2] = {1,0,0} end if
   end for
   -- second stage, pass 2, left to right, 011 -> 100
   for i=1 to length(res)-2 do
       if res[i..i+2]={0,1,1} then res[i..i+2] = {1,0,0} end if
   end for
   return to_int(res)

end function

function zadd(integer a, b)

   sequence {sa,sb} = to_bits2(a,b)
   return zcleanup(reverse(sq_add(sa,sb)))

end function

function zinc(integer a)

   return zadd(a,0b1)

end function

function zsub(integer a, b)

   sequence {sa,sb} = to_bits2(a,b)
   sequence res = reverse(sq_sub(sa,sb))
   -- (/not/ combined with the first pass of the add routine!)
   for i=1 to length(res)-2 do
       switch res[i..i+2] do
           case {1, 0, 0}: res[i..i+2] = {0,1,1}
           case {1,-1, 0}: res[i..i+2] = {0,0,1}
           case {1,-1, 1}: res[i..i+2] = {0,0,2}
           case {1, 0,-1}: res[i..i+2] = {0,1,0}
           case {2, 0, 0}: res[i..i+2] = {1,1,1}
           case {2,-1, 0}: res[i..i+2] = {1,0,1}
           case {2,-1, 1}: res[i..i+2] = {1,0,2}
           case {2, 0,-1}: res[i..i+2] = {1,1,0}
       end switch
   end for
   -- copied from PicoLisp: {1,-1} -> {0,1} and {2,-1} -> {1,1}
   for i=1 to length(res)-1 do
       switch res[i..i+1] do
           case {1,-1}: res[i..i+1] = {0,1}
           case {2,-1}: res[i..i+1] = {1,1}
       end switch
   end for
   if find(-1,res) then ?9/0 end if -- sanity check
   return zcleanup(res)

end function

function zdec(integer a)

   return zsub(a,0b1)

end function

function zmul(integer a, b) integer res = 0

   sequence mult = {a,zadd(a,a)}   -- (as per task desc)
   integer bits = 2
   while bits<b do
       mult = append(mult,zadd(mult[$],mult[$-1]))
       bits *= 2
   end while
   integer bit = 1
   while b do
       if and_bits(b,1) then
           res = zadd(res,mult[bit])
       end if
       b = floor(b/2)
       bit += 1
   end while
   return res

end function

function zdiv(integer a, b) integer res = 0

   sequence mult = {b,zadd(b,b)}
   integer bits = 2
   while mult[$]<a do
       mult = append(mult,zadd(mult[$],mult[$-1]))
       bits *= 2
   end while
   for i=length(mult) to 1 by -1 do
       integer mi = mult[i]
       if mi<=a then
           res = zadd(res,bits)
           a = zsub(a,mi)
           if a=0 then exit end if
       end if
       bits = floor(bits/2)
   end for
   return {res,a} -- (a is the remainder)

end function

for i=0 to 20 do

   integer zi = zeckendorf(i)
   atom d = decimal(zi)
   printf(1,"%2d: %7b (%d)\n",{i,zi,d})

end for

procedure test(atom a, string op, atom b, object res, string expected)

   string zres = iff(atom(res)?zstr(res):join(zstr(res)," rem ")),
          dres = sprintf(iff(atom(res)?"%d":"%d rem %d"),decimal(res)),
          aka = sprintf("aka %d %s %d = %s",{decimal(a),op,decimal(b),dres}),
          ok = iff(zres=expected?"":" *** ERROR ***!!")
   printf(1,"%s %s %s = %s, %s %s\n",{zstr(a),op,zstr(b),zres,aka,ok})

end procedure

test(0b0,"+",0b0,zadd(0b0,0b0),"0") test(0b101,"+",0b101,zadd(0b101,0b101),"10000") test(0b10100,"-",0b1000,zsub(0b10100,0b1000),"1001") test(0b100100,"-",0b1000,zsub(0b100100,0b1000),"10100") test(0b1001,"*",0b101,zmul(0b1001,0b101),"1000100") test(0b1000101,"/",0b101,zdiv(0b1000101,0b101),"1001 rem 1")

test(0b10,"+",0b10,zadd(0b10,0b10),"101") test(0b101,"+",0b10,zadd(0b101,0b10),"1001") test(0b1001,"+",0b1001,zadd(0b1001,0b1001),"10101") test(0b10101,"+",0b1000,zadd(0b10101,0b1000),"100101") test(0b100101,"+",0b10101,zadd(0b100101,0b10101),"1010000") test(0b1000,"-",0b101,zsub(0b1000,0b101),"1") test(0b10101010,"-",0b1010101,zsub(0b10101010,0b1010101),"1000000") test(0b1001,"*",0b101,zmul(0b1001,0b101),"1000100") test(0b101010,"+",0b101,zadd(0b101010,0b101),"1000100")

test(0b10100,"+",0b1010,zadd(0b10100,0b1010),"101000") test(0b101000,"-",0b1010,zsub(0b101000,0b1010),"10100")

test(0b100010,"*",0b100101,zmul(0b100010,0b100101),"100001000001") test(0b100001000001,"/",0b100,zdiv(0b100001000001,0b100),"101010001 rem 0") test(0b101000101,"*",0b101001,zmul(0b101000101,0b101001),"101010000010101") test(0b101010000010101,"/",0b100,zdiv(0b101010000010101,0b100),"1001010001001 rem 10")

test(0b10100010010100,"+",0b1001000001,zadd(0b10100010010100,0b1001000001),"100000000010101") test(0b10100010010100,"-",0b1001000001,zsub(0b10100010010100,0b1001000001),"10010001000010") test(0b10000,"*",0b1001000001,zmul(0b10000,0b1001000001),"10100010010100") test(0b1010001010000001001,"/",0b100000000100000,zdiv(0b1010001010000001001,0b100000000100000),"10001 rem 10100001010101")

test(0b10100,"+",0b1010,zadd(0b10100,0b1010),"101000") test(0b10100,"-",0b1010,zsub(0b10100,0b1010),"101") test(0b10100,"*",0b1010,zmul(0b10100,0b1010),"101000001") test(0b10100,"/",0b1010,zdiv(0b10100,0b1010),"1 rem 101") integer m = zmul(0b10100,0b1010) test(m,"/",0b1010,zdiv(m,0b1010),"10100 rem 0")</lang>

Output:
 0:       0 (0)
 1:       1 (1)
 2:      10 (2)
 3:     100 (3)
 4:     101 (4)
 5:    1000 (5)
 6:    1001 (6)
 7:    1010 (7)
 8:   10000 (8)
 9:   10001 (9)
10:   10010 (10)
11:   10100 (11)
12:   10101 (12)
13:  100000 (13)
14:  100001 (14)
15:  100010 (15)
16:  100100 (16)
17:  100101 (17)
18:  101000 (18)
19:  101001 (19)
20:  101010 (20)
0 + 0 = 0, aka 0 + 0 = 0
101 + 101 = 10000, aka 4 + 4 = 8
10100 - 1000 = 1001, aka 11 - 5 = 6
100100 - 1000 = 10100, aka 16 - 5 = 11
1001 * 101 = 1000100, aka 6 * 4 = 24
1000101 / 101 = 1001 rem 1, aka 25 / 4 = 6 rem 1
10 + 10 = 101, aka 2 + 2 = 4
101 + 10 = 1001, aka 4 + 2 = 6
1001 + 1001 = 10101, aka 6 + 6 = 12
10101 + 1000 = 100101, aka 12 + 5 = 17
100101 + 10101 = 1010000, aka 17 + 12 = 29
1000 - 101 = 1, aka 5 - 4 = 1
10101010 - 1010101 = 1000000, aka 54 - 33 = 21
1001 * 101 = 1000100, aka 6 * 4 = 24
101010 + 101 = 1000100, aka 20 + 4 = 24
10100 + 1010 = 101000, aka 11 + 7 = 18
101000 - 1010 = 10100, aka 18 - 7 = 11
100010 * 100101 = 100001000001, aka 15 * 17 = 255
100001000001 / 100 = 101010001 rem 0, aka 255 / 3 = 85 rem 0
101000101 * 101001 = 101010000010101, aka 80 * 19 = 1520
101010000010101 / 100 = 1001010001001 rem 10, aka 1520 / 3 = 506 rem 2
10100010010100 + 1001000001 = 100000000010101, aka 888 + 111 = 999
10100010010100 - 1001000001 = 10010001000010, aka 888 - 111 = 777
10000 * 1001000001 = 10100010010100, aka 8 * 111 = 888
1010001010000001001 / 100000000100000 = 10001 rem 10100001010101, aka 9876 / 1000 = 9 rem 876
10100 + 1010 = 101000, aka 11 + 7 = 18
10100 - 1010 = 101, aka 11 - 7 = 4
10100 * 1010 = 101000001, aka 11 * 7 = 77
10100 / 1010 = 1 rem 101, aka 11 / 7 = 1 rem 4
101000001 / 1010 = 10100 rem 0, aka 77 / 7 = 11 rem 0

PicoLisp

<lang>(seed (in "/dev/urandom" (rd 8)))

(de unpad (Lst)

  (while (=0 (car Lst))
     (pop 'Lst) )
  Lst )

(de numz (N)

  (let Fibs (1 1)
     (while (>= N (+ (car Fibs) (cadr Fibs)))
        (push 'Fibs (+ (car Fibs) (cadr Fibs))) )
     (make
        (for I (uniq Fibs)
           (if (> I N)
              (link 0)
              (link 1)
              (dec 'N I) ) ) ) ) )

(de znum (Lst)

  (let Fibs (1 1)
     (do (dec (length Lst))
        (push 'Fibs (+ (car Fibs) (cadr Fibs))) )
     (sum
        '((X Y) (unless (=0 X) Y))
        Lst
        (uniq Fibs) ) ) )
           

(de incz (Lst)

  (addz Lst (1)) )

(de decz (Lst)

  (subz Lst (1)) )
  

(de addz (Lst1 Lst2)

  (let Max (max (length Lst1) (length Lst2))
     (reorg
        (mapcar + (need Max Lst1 0) (need Max Lst2 0)) ) ) )

(de subz (Lst1 Lst2)

  (use (@A @B)
     (let
        (Max (max (length Lst1) (length Lst2))
           Lst (mapcar - (need Max Lst1 0) (need Max Lst2 0)) )
        (loop 
           (while (match '(@A 1 0 0 @B) Lst)
              (setq Lst (append @A (0 1 1) @B)) )
           (while (match '(@A 1 -1 0 @B) Lst)
              (setq Lst (append @A (0 0 1) @B)) )
           (while (match '(@A 1 -1 1 @B) Lst)
              (setq Lst (append @A (0 0 2) @B)) )
           (while (match '(@A 1 0 -1 @B) Lst)
              (setq Lst (append @A (0 1 0) @B)) )
           (while (match '(@A 2 0 0 @B) Lst)
              (setq Lst (append @A (1 1 1) @B)) )
           (while (match '(@A 2 -1 0 @B) Lst)
              (setq Lst (append @A (1 0 1) @B)) )
           (while (match '(@A 2 -1 1 @B) Lst)
              (setq Lst (append @A (1 0 2) @B)) )
           (while (match '(@A 2 0 -1 @B) Lst)
              (setq Lst (append @A (1 1 0) @B)) )
           (while (match '(@A 1 -1) Lst)
              (setq Lst (append @A (0 1))) )
           (while (match '(@A 2 -1) Lst)
              (setq Lst (append @A (1 1))) )
           (NIL (match '(@A -1 @B) Lst)) )
        (reorg (unpad Lst)) ) ) )

(de mulz (Lst1 Lst2)

  (let (Sums (list Lst1) Mulz (0))
     (mapc
        '((X)
           (when (= 1 (car X))
              (setq Mulz (addz (cdr X) Mulz)) ) 
           Mulz )
        (mapcar
           '((X)
              (cons
                 X 
                 (push 'Sums (addz (car Sums) (cadr Sums))) ) )
           (reverse Lst2) ) ) ) ) 
         

(de divz (Lst1 Lst2)

  (let Q 0
     (while (lez Lst2 Lst1)
        (setq Lst1 (subz Lst1 Lst2))
        (setq Q (incz Q)) )
     (list Q (or Lst1 (0))) ) )

(de reorg (Lst)

  (use (@A @B)
     (let Lst (reverse Lst)
        (loop
           (while (match '(@A 1 1 @B) Lst)
              (if @B
                 (inc (nth @B 1))
                 (setq @B (1)) )
              (setq Lst (append @A (0 0) @B) ) )
           (while (match '(@A 2 @B) Lst)
              (inc
                 (if (cdr @A) 
                    (tail 2 @A)
                    @A ) )
              (if @B
                 (inc (nth @B 1))
                 (setq @B (1)) )
              (setq Lst (append @A (0) @B)) )
           (NIL
              (or
                 (match '(@A 1 1 @B) Lst)
                 (match '(@A 2 @B) Lst) ) ) )
        (reverse Lst) ) ) )

(de lez (Lst1 Lst2)

  (let Max (max (length Lst1) (length Lst2))
     (<= (need Max Lst1 0) (need Max Lst2 0)) ) )

(let (X 0 Y 0)

  (do 1024
     (setq X (rand 1 1024))
     (setq Y (rand 1 1024))
     (test (numz (+ X Y)) (addz (numz X) (numz Y)))
     (test (numz (* X Y)) (mulz (numz X) (numz Y)))
     (test (numz (+ X 1)) (incz (numz X))) )
  (do 1024
     (setq X (rand 129 1024))
     (setq Y (rand 1 128))
     (test (numz (- X Y)) (subz (numz X) (numz Y)))
     (test (numz (/ X Y)) (car (divz (numz X) (numz Y))))
     (test (numz (% X Y)) (cadr (divz (numz X) (numz Y))))
     (test (numz (- X 1)) (decz (numz X))) ) )

(bye)</lang>

Python

<lang python>import copy

class Zeckendorf:

   def __init__(self, x='0'):
       q = 1
       i = len(x) - 1
       self.dLen = int(i / 2)
       self.dVal = 0
       while i >= 0:
           self.dVal = self.dVal + (ord(x[i]) - ord('0')) * q
           q = q * 2
           i = i -1
   def a(self, n):
       i = n
       while True:
           if self.dLen < i:
               self.dLen = i
           j = (self.dVal >> (i * 2)) & 3
           if j == 0 or j == 1:
               return
           if j == 2:
               if (self.dVal >> ((i + 1) * 2) & 1) != 1:
                   return
               self.dVal = self.dVal + (1 << (i * 2 + 1))
               return
           if j == 3:
               temp = 3 << (i * 2)
               temp = temp ^ -1
               self.dVal = self.dVal & temp
               self.b((i + 1) * 2)
           i = i + 1
   def b(self, pos):
       if pos == 0:
           self.inc()
           return
       if (self.dVal >> pos) & 1 == 0:
           self.dVal = self.dVal + (1 << pos)
           self.a(int(pos / 2))
           if pos > 1:
               self.a(int(pos / 2) - 1)
       else:
           temp = 1 << pos
           temp = temp ^ -1
           self.dVal = self.dVal & temp
           self.b(pos + 1)
           self.b(pos - (2 if pos > 1 else 1))
   def c(self, pos):
       if (self.dVal >> pos) & 1 == 1:
           temp = 1 << pos
           temp = temp ^ -1
           self.dVal = self.dVal & temp
           return
       self.c(pos + 1)
       if pos > 0:
           self.b(pos - 1)
       else:
           self.inc()
   def inc(self):
       self.dVal = self.dVal + 1
       self.a(0)
   def __add__(self, rhs):
       copy = self
       rhs_dVal = rhs.dVal
       limit = (rhs.dLen + 1) * 2
       for gn in range(0, limit):
           if ((rhs_dVal >> gn) & 1) == 1:
               copy.b(gn)
       return copy
   def __sub__(self, rhs):
       copy = self
       rhs_dVal = rhs.dVal
       limit = (rhs.dLen + 1) * 2
       for gn in range(0, limit):
           if (rhs_dVal >> gn) & 1 == 1:
               copy.c(gn)
       while (((copy.dVal >> ((copy.dLen * 2) & 31)) & 3) == 0) or (copy.dLen == 0):
           copy.dLen = copy.dLen - 1
       return copy
   def __mul__(self, rhs):
       na = copy.deepcopy(rhs)
       nb = copy.deepcopy(rhs)
       nr = Zeckendorf()
       dVal = self.dVal
       for i in range(0, (self.dLen + 1) * 2):
           if ((dVal >> i) & 1) > 0:
               nr = nr + nb
           nt = copy.deepcopy(nb)
           nb = nb + na
           na = copy.deepcopy(nt)
       return nr
   def __str__(self):
       dig = ["00", "01", "10"]
       dig1 = ["", "1", "10"]
       if self.dVal == 0:
           return '0'
       idx = (self.dVal >> ((self.dLen * 2) & 31)) & 3
       sb = dig1[idx]
       i = self.dLen - 1
       while i >= 0:
           idx = (self.dVal >> (i * 2)) & 3
           sb = sb + dig[idx]
           i = i - 1
       return sb
  1. main

print "Addition:" g = Zeckendorf("10") g = g + Zeckendorf("10") print g g = g + Zeckendorf("10") print g g = g + Zeckendorf("1001") print g g = g + Zeckendorf("1000") print g g = g + Zeckendorf("10101") print g print

print "Subtraction:" g = Zeckendorf("1000") g = g - Zeckendorf("101") print g g = Zeckendorf("10101010") g = g - Zeckendorf("1010101") print g print

print "Multiplication:" g = Zeckendorf("1001") g = g * Zeckendorf("101") print g g = Zeckendorf("101010") g = g + Zeckendorf("101") print g</lang>

Output:
Addition:
101
1001
10101
100101
1010000

Subtraction:
1
1000000

Multiplication:
1000100
1000100

Racket

This implementation only handles natural (non-negative numbers). The algorithms for addition and subtraction use the techniques explained in the paper "Efficient algorithms for Zeckendorf arithmetic" (http://arxiv.org/pdf/1207.4497.pdf).

<lang racket>#lang racket (require math)

(define sqrt5 (sqrt 5)) (define phi (* 0.5 (+ 1 sqrt5)))

What is the nth fibonnaci number, shifted by 2 so that
F(0) = 1, F(1) = 2, ...?

(define (F n)

 (fibonacci (+ n 2)))
What is the largest n such that F(n) <= m?

(define (F* m)

 (let ([n (- (inexact->exact (round (/ (log (* m sqrt5)) (log phi)))) 2)])
   (if (<= (F n) m) n (sub1 n))))

(define (zeck->natural z)

 (for/sum ([i (reverse z)]
           [j (in-naturals)])
   (* i (F j))))
           

(define (natural->zeck n)

 (if (zero? n)
     null
     (for/list ([i (in-range (F* n) -1 -1)])
       (let ([f (F i)])
         (cond [(>= n f) (set! n (- n f))
                         1]
               [else 0])))))
Extend list to the right to a length of len with repeated padding elements

(define (pad lst len [padding 0])

 (append lst (make-list (- len (length lst)) padding)))
Strip padding elements from the left of the list

(define (unpad lst [padding 0])

 (cond [(null? lst) lst]
       [(equal? (first lst) padding) (unpad (rest lst) padding)]
       [else lst]))
Run a filter function across a window in a list from left to right

(define (left->right width fn)

 (λ (lst)
   (let F ([a lst])
     (if (< (length a) width) 
         a
         (let ([f (fn (take a width))])
           (cons (first f) (F (append (rest f) (drop a width)))))))))
Run a function fn across a window in a list from right to left

(define (right->left width fn)

 (λ (lst)
   (let F ([a lst])
     (if (< (length a) width) 
         a
         (let ([f (fn (take-right a width))])
           (append (F (append (drop-right a width) (drop-right f 1)))
                   (list (last f))))))))
(a0 a1 a2 ... an) -> (a0 a1 a2 ... (fn ... an))

(define (replace-tail width fn)

 (λ (lst)
   (append (drop-right lst width) (fn (take-right lst width)))))

(define (rule-a lst)

 (match lst
   [(list 0 2 0 x) (list 1 0 0 (add1 x))]
   [(list 0 3 0 x) (list 1 1 0 (add1 x))]
   [(list 0 2 1 x) (list 1 1 0 x)]
   [(list 0 1 2 x) (list 1 0 1 x)]
   [else lst]))

(define (rule-a-tail lst)

 (match lst
   [(list x 0 3 0) (list x 1 1 1)]
   [(list x 0 2 0) (list x 1 0 1)]
   [(list 0 1 2 0) (list 1 0 1 0)]
   [(list x y 0 3) (list x y 1 1)]
   [(list x y 0 2) (list x y 1 0)]
   [(list x 0 1 2) (list x 1 0 0)]
   [else lst]))

(define (rule-b lst)

 (match lst
   [(list 0 1 1) (list 1 0 0)]
   [else lst]))

(define (rule-c lst)

 (match lst
   [(list 1 0 0) (list 0 1 1)]
   [(list 1 -1 0) (list 0 0 1)]
   [(list 1 -1 1) (list 0 0 2)]
   [(list 1 0 -1) (list 0 1 0)]
   [(list 2 0 0) (list 1 1 1)]
   [(list 2 -1 0) (list 1 0 1)]
   [(list 2 -1 1) (list 1 0 2)]
   [(list 2 0 -1) (list 1 1 0)]
   [else lst]))

(define (zeck-combine op y z [f identity])

 (let* ([bits (max (add1 (length y)) (add1 (length z)) 4)]
        [f0 (λ (x) (pad (reverse x) bits))]
        [f1 (left->right 4 rule-a)]
        [f2 (replace-tail 4 rule-a-tail)]
        [f3 (right->left 3 rule-b)]
        [f4 (left->right 3 rule-b)])
   ((compose1 unpad f4 f3 f2 f1 f reverse) (map op (f0 y) (f0 z)))))

(define (zeck+ y z)

 (zeck-combine + y z))

(define (zeck- y z)

 (when (zeck< y z) (error (format "~a" `(zeck-: cannot subtract since ,y < ,z))))
 (zeck-combine - y z (left->right 3 rule-c)))

(define (zeck* y z)

 (define (M ry Zn Zn_1 [acc null])
   (if (null? ry) 
       acc
       (M (rest ry) (zeck+ Zn Zn_1) Zn 
          (if (zero? (first ry)) acc (zeck+ acc Zn))))) 
 (cond [(zeck< z y) (zeck* z y)]
       [(null? y) null]               ; 0 * z -> 0
       [else (M (reverse y) z z)]))

(define (zeck-quotient/remainder y z)

 (define (M Zn acc)
   (if (zeck< y Zn) 
       (drop-right acc 1)
       (M (zeck+ Zn (first acc)) (cons Zn acc))))
 (define (D x m [acc null])
   (if (null? m)
       (values (reverse acc) x)
       (let* ([v (first m)]
              [smaller (zeck< v x)]
              [bit (if smaller 1 0)]
              [x_ (if smaller (zeck- x v) x)])
         (D x_ (rest m) (cons bit acc)))))
 (D y (M z (list z))))

(define (zeck-quotient y z)

 (let-values ([(quotient _) (zeck-quotient/remainder y z)])
   quotient))

(define (zeck-remainder y z)

 (let-values ([(_ remainder) (zeck-quotient/remainder y z)])
   remainder))

(define (zeck-add1 z)

 (zeck+ z '(1)))

(define (zeck= y z)

 (equal? (unpad y) (unpad z)))

(define (zeck< y z)

 ; Compare equal-length unpadded zecks
 (define (LT a b)
   (if (null? a) 
       #f
       (let ([a0 (first a)] [b0 (first b)])
         (if (= a0 b0) 
             (LT (rest a) (rest b))
             (= a0 0)))))
       
 (let* ([a (unpad y)] [len-a (length a)]
        [b (unpad z)] [len-b (length b)])
   (cond [(< len-a len-b) #t]
         [(> len-a len-b) #f]
         [else (LT a b)])))

(define (zeck> y z)

 (not (or (zeck= y z) (zeck< y z))))


Examples

(define (example op-name op a b)

 (let* ([y (natural->zeck a)]
        [z (natural->zeck b)]
        [x (op y z)]
        [c (zeck->natural x)])
   (printf "~a ~a ~a = ~a ~a ~a = ~a = ~a\n"
           a op-name b y op-name z x c)))

(example '+ zeck+ 888 111) (example '- zeck- 888 111) (example '* zeck* 8 111) (example '/ zeck-quotient 9876 1000) (example '% zeck-remainder 9876 1000) </lang>

Output:
888 + 111 = (1 0 1 0 0 0 1 0 0 1 0 1 0 0) + (1 0 0 1 0 0 0 0 0 1) = (1 0 0 0 0 0 0 0 0 0 1 0 1 0 1) = 999
888 - 111 = (1 0 1 0 0 0 1 0 0 1 0 1 0 0) - (1 0 0 1 0 0 0 0 0 1) = (1 0 0 1 0 0 0 1 0 0 0 0 1 0) = 777
8 * 111 = (1 0 0 0 0) * (1 0 0 1 0 0 0 0 0 1) = (1 0 1 0 0 0 1 0 0 1 0 1 0 0) = 888
9876 / 1000 = (1 0 1 0 0 0 1 0 1 0 0 0 0 0 0 1 0 0 1) / (1 0 0 0 0 0 0 0 0 1 0 0 0 0 0) = (1 0 0 0 1) = 9
9876 % 1000 = (1 0 1 0 0 0 1 0 1 0 0 0 0 0 0 1 0 0 1) % (1 0 0 0 0 0 0 0 0 1 0 0 0 0 0) = (1 0 1 0 0 0 0 1 0 1 0 1 0 1) = 876

Raku

(formerly Perl 6) This is a somewhat limited implementation of Zeckendorf arithmetic operators. They only handle positive integer values. There are no actual calculations, everything is done with string manipulations, so it doesn't matter what glyphs you use for 1 and 0.

Works with: rakudo version 2019.03

Implemented arithmetic operators:

 addition: +z
 subtraction: -z
 multiplication: *z
 division: /z (more of a divmod really)
 post increment: ++z
 post decrement: --z

Comparison operators:

 equal eqz
 not equal nez
 greater than gtz
 less than ltz

<lang perl6>my $z1 = '1'; # glyph to use for a '1' my $z0 = '0'; # glyph to use for a '0'

sub zorder($a) { ($z0 lt $z1) ?? $a !! $a.trans([$z0, $z1] => [$z1, $z0]) };

                1. Zeckendorf comparison operators #########
  1. less than

sub infix:<ltz>($a, $b) { $a.&zorder lt $b.&zorder };

  1. greater than

sub infix:<gtz>($a, $b) { $a.&zorder gt $b.&zorder };

  1. equal

sub infix:<eqz>($a, $b) { $a eq $b };

  1. not equal

sub infix:<nez>($a, $b) { $a ne $b };

                1. Operators for Zeckendorf arithmetic ########
  1. post increment

sub postfix:<++z>($a is rw) {

   $a = ("$z0$z0"~$a).subst(/("$z0$z0")($z1+ %% $z0)?$/,
     -> $/ { "$z0$z1" ~ ($1 ?? $z0 x $1.chars !! ) });
   $a ~~ s/^$z0+//;
   $a

}

  1. post decrement

sub postfix:<--z>($a is rw) {

   $a.=subst(/$z1($z0*)$/,
     -> $/ {$z0 ~ "$z1$z0" x $0.chars div 2 ~ $z1 x $0.chars mod 2});
   $a ~~ s/^$z0+(.+)$/$0/;
   $a

}

  1. addition

sub infix:<+z>($a is copy, $b is copy) { $a++z; $a++z while $b--z nez $z0; $a };

  1. subtraction

sub infix:<-z>($a is copy, $b is copy) { $a--z; $a--z while $b--z nez $z0; $a };

  1. multiplication

sub infix:<*z>($a, $b) {

   return $z0 if $a eqz $z0 or $b eqz $z0;
   return $a if $b eqz $z1;
   return $b if $a eqz $z1;
   my $c = $a;
   my $d = $z1;
   repeat { 
        my $e = $z0;
        repeat { $c++z; $e++z } until $e eqz $a;
        $d++z;
   } until $d eqz $b;
   $c

};

  1. division (really more of a div mod)

sub infix:</z>($a is copy, $b is copy) {

   fail "Divide by zero" if $b eqz $z0;
   return $a if $a eqz $z0 or $b eqz $z1;
   my $c = $z0;
   repeat { 
       my $d = $b +z ($z1 ~ $z0);
       $c++z;
       $a++z;
       $a--z while $d--z nez $z0
   } until $a ltz $b;
   $c ~= " remainder $a" if $a nez $z0;
   $c

};

                                            1. Testing ######################
  1. helper sub to translate constants into the particular glyphs you used

sub z($a) { $a.trans([<1 0>] => [$z1, $z0]) };

say "Using the glyph '$z1' for 1 and '$z0' for 0\n";

my $fmt = "%-22s = %15s %s\n";

my $zeck = $z1;

printf( $fmt, "$zeck++z", $zeck++z, '# increment' ) for 1 .. 10;

printf $fmt, "$zeck +z {z('1010')}", $zeck +z= z('1010'), '# addition';

printf $fmt, "$zeck -z {z('100')}", $zeck -z= z('100'), '# subtraction';

printf $fmt, "$zeck *z {z('100101')}", $zeck *z= z('100101'), '# multiplication';

printf $fmt, "$zeck /z {z('100')}", $zeck /z= z('100'), '# division';

printf( $fmt, "$zeck--z", $zeck--z, '# decrement' ) for 1 .. 5;

printf $fmt, "$zeck *z {z('101001')}", $zeck *z= z('101001'), '# multiplication';

printf $fmt, "$zeck /z {z('100')}", $zeck /z= z('100'), '# division';</lang>

Testing Output

Using the glyph '1' for 1 and '0' for 0

1++z                   =              10  # increment
10++z                  =             100  # increment
100++z                 =             101  # increment
101++z                 =            1000  # increment
1000++z                =            1001  # increment
1001++z                =            1010  # increment
1010++z                =           10000  # increment
10000++z               =           10001  # increment
10001++z               =           10010  # increment
10010++z               =           10100  # increment
10100 +z 1010          =          101000  # addition
101000 -z 100          =          100010  # subtraction
100010 *z 100101       =    100001000001  # multiplication
100001000001 /z 100    =       101010001  # division
101010001--z           =       101010000  # decrement
101010000--z           =       101001010  # decrement
101001010--z           =       101001001  # decrement
101001001--z           =       101001000  # decrement
101001000--z           =       101000101  # decrement
101000101 *z 101001    = 101010000010101  # multiplication
101010000010101 /z 100 = 1001010001001 remainder 10  # division

Output using 'X' for 1 and 'O' for 0:

Using the glyph 'X' for 1 and 'O' for 0

X++z                   =              XO  # increment
XO++z                  =             XOO  # increment
XOO++z                 =             XOX  # increment
XOX++z                 =            XOOO  # increment
XOOO++z                =            XOOX  # increment
XOOX++z                =            XOXO  # increment
XOXO++z                =           XOOOO  # increment
XOOOO++z               =           XOOOX  # increment
XOOOX++z               =           XOOXO  # increment
XOOXO++z               =           XOXOO  # increment
XOXOO +z XOXO          =          XOXOOO  # addition
XOXOOO -z XOO          =          XOOOXO  # subtraction
XOOOXO *z XOOXOX       =    XOOOOXOOOOOX  # multiplication
XOOOOXOOOOOX /z XOO    =       XOXOXOOOX  # division
XOXOXOOOX--z           =       XOXOXOOOO  # decrement
XOXOXOOOO--z           =       XOXOOXOXO  # decrement
XOXOOXOXO--z           =       XOXOOXOOX  # decrement
XOXOOXOOX--z           =       XOXOOXOOO  # decrement
XOXOOXOOO--z           =       XOXOOOXOX  # decrement
XOXOOOXOX *z XOXOOX    = XOXOXOOOOOXOXOX  # multiplication
XOXOXOOOOOXOXOX /z XOO = XOOXOXOOOXOOX remainder XO  # division

Scala

Works with: Scala version 2.13.1

The addition is an implementation of an algorithm suggested in http[:]//arxiv.org/pdf/1207.4497.pdf: Efficient Algorithms for Zeckendorf Arithmetic. <lang Scala> import scala.collection.mutable.ListBuffer

object ZeckendorfArithmetic extends App {


 val elapsed: (=> Unit) => Long = f => {
   val s = System.currentTimeMillis
   f
   (System.currentTimeMillis - s) / 1000
 }
 val add: (Z, Z) => Z = (z1, z2) => z1 + z2
 val subtract: (Z, Z) => Z = (z1, z2) => z1 - z2
 val multiply: (Z, Z) => Z = (z1, z2) => z1 * z2
 val divide: (Z, Z) => Option[Z] = (z1, z2) => z1 / z2
 val modulo: (Z, Z) => Option[Z] = (z1, z2) => z1 % z2
 val ops = Map(("+", add), ("-", subtract), ("*", multiply), ("/", divide), ("%", modulo))
 val calcs = List(
   (Z("101"), "+", Z("10100"))
   , (Z("101"), "-", Z("10100"))
   , (Z("101"), "*", Z("10100"))
   , (Z("101"), "/", Z("10100"))
   , (Z("-1010101"), "+", Z("10100"))
   , (Z("-1010101"), "-", Z("10100"))
   , (Z("-1010101"), "*", Z("10100"))
   , (Z("-1010101"), "/", Z("10100"))
   , (Z("1000101010"), "+", Z("10101010"))
   , (Z("1000101010"), "-", Z("10101010"))
   , (Z("1000101010"), "*", Z("10101010"))
   , (Z("1000101010"), "/", Z("10101010"))
   , (Z("10100"), "+", Z("1010"))
   , (Z("100101"), "-", Z("100"))
   , (Z("1010101010101010101"), "+", Z("-1010101010101"))
   , (Z("1010101010101010101"), "-", Z("-1010101010101"))
   , (Z("1010101010101010101"), "*", Z("-1010101010101"))
   , (Z("1010101010101010101"), "/", Z("-1010101010101"))
   , (Z("1010101010101010101"), "%", Z("-1010101010101"))
   , (Z("1010101010101010101"), "+", Z("101010101010101"))
   , (Z("1010101010101010101"), "-", Z("101010101010101"))
   , (Z("1010101010101010101"), "*", Z("101010101010101"))
   , (Z("1010101010101010101"), "/", Z("101010101010101"))
   , (Z("1010101010101010101"), "%", Z("101010101010101"))
   , (Z("10101010101010101010"), "+", Z("1010101010101010"))
   , (Z("10101010101010101010"), "-", Z("1010101010101010"))
   , (Z("10101010101010101010"), "*", Z("1010101010101010"))
   , (Z("10101010101010101010"), "/", Z("1010101010101010"))
   , (Z("10101010101010101010"), "%", Z("1010101010101010"))
   , (Z("1010"), "%", Z("10"))
   , (Z("1010"), "%", Z("-10"))
   , (Z("-1010"), "%", Z("10"))
   , (Z("-1010"), "%", Z("-10"))
   , (Z("100"), "/", Z("0"))
   , (Z("100"), "%", Z("0"))
 )
 val iadd: (BigInt, BigInt) => BigInt = (a, b) => a + b
 val isub: (BigInt, BigInt) => BigInt = (a, b) => a - b
 // just for result checking:
 import Z._
 val imul: (BigInt, BigInt) => BigInt = (a, b) => a * b
 val idiv: (BigInt, BigInt) => Option[BigInt] = (a, b) => if (b == 0) None else Some(a / b)
 val imod: (BigInt, BigInt) => Option[BigInt] = (a, b) => if (b == 0) None else Some(a % b)
 val iops = Map(("+", iadd), ("-", isub), ("*", imul), ("/", idiv), ("%", imod))
 case class Z(var zs: String) {
   import Z._
   require((zs.toSet -- Set('-', '0', '1') == Set()) && (!zs.contains("11")))
   //--- fa(summand1.z,summand2.z) --------------------------
   val fa: (BigInt, BigInt) => BigInt = (z1, z2) => {
     val v = z1.toString.toCharArray.map(_.asDigit).reverse.padTo(5, 0).zipAll(z2.toString.toCharArray.map(_.asDigit).reverse, 0, 0)
     val arr1 = (v.map(p => p._1 + p._2) :+ 0).reverse
     (0 to arr1.length - 4) foreach { i => //stage1
       val a = arr1.slice(i, i + 4).toList
       val b = a.foldRight("")("" + _ + _) dropRight 1
       val a1 = b match {
         case "020" => List(1, 0, 0, a(3) + 1)
         case "030" => List(1, 1, 0, a(3) + 1)
         case "021" => List(1, 1, 0, a(3))
         case "012" => List(1, 0, 1, a(3))
         case _ => a
       }
       0 to 3 foreach { j => arr1(j + i) = a1(j) }
     }
     val arr2 = arr1.foldRight("")("" + _ + _)
       .replace("0120", "1010").replace("030", "111").replace("003", "100").replace("020", "101")
       .replace("003", "100").replace("012", "101").replace("021", "110")
       .replace("02", "10").replace("03", "11")
       .reverse.toArray
     (0 to arr2.length - 3) foreach { i => //stage2, step1
       val a = arr2.slice(i, i + 3).toList
       val b = a.foldRight("")("" + _ + _)
       val a1 = b match {
         case "110" => List('0', '0', '1')
         case _ => a
       }
       0 to 2 foreach { j => arr2(j + i) = a1(j) }
     }
     val arr3 = arr2.foldRight("")("" + _ + _).concat("0").reverse.toArray
     (0 to arr3.length - 3) foreach { i => //stage2, step2
       val a = arr3.slice(i, i + 3).toList
       val b = a.foldRight("")("" + _ + _)
       val a1 = b match {
         case "011" => List('1', '0', '0')
         case _ => a
       }
       0 to 2 foreach { j => arr3(j + i) = a1(j) }
     }
     BigInt(arr3.foldRight("")("" + _ + _))
   }
   //--- fs(minuend.z,subtrahend.z) -------------------------
   val fs: (BigInt, BigInt) => BigInt = (min, sub) => {
     val zmvr = min.toString.toCharArray.map(_.asDigit).reverse
     val zsvr = sub.toString.toCharArray.map(_.asDigit).reverse.padTo(zmvr.length, 0)
     val v = zmvr.zipAll(zsvr, 0, 0).reverse
     val last = v.length - 1
     val zma = zmvr.reverse.toArray
     val zsa = zsvr.reverse.toArray
     for (i <- (0 to last).reverse) {
       val e = zma(i) - zsa(i)
       if (e < 0) {
         zma(i - 1) = zma(i - 1) - 1
         zma(i) = 0
         val part = Z(((i to last).map(zma(_))).foldRight("")("" + _ + _))
         val carry = Z("1".padTo(last - i, "0").foldRight("")("" + _ + _))
         val sum = part + carry
         val sums = sum.z.toString
         (1 to sum.size) foreach { j => zma(last - sum.size + j) = sums(j - 1).asDigit }
         if (zma(i - 1) < 0) {
           for (j <- (0 until i).reverse) {
             if (zma(j) < 0) {
               zma(j - 1) = zma(j - 1) - 1
               zma(j) = 0
               val part = Z(((j to last).map(zma(_))).foldRight("")("" + _ + _))
               val carry = Z("1".padTo(last - j, "0").foldRight("")("" + _ + _))
               val sum = part + carry
               val sums = sum.z.toString
               (1 to sum.size) foreach { k => zma(last - sum.size + k) = sums(k - 1).asDigit }
             }
           }
         }
       }
       else zma(i) = e
       zsa(i) = 0
     }
     BigInt(zma.foldRight("")("" + _ + _))
   }
   //--- fm(multiplicand.z,multplier.z) ---------------------
   val fm: (BigInt, BigInt) => BigInt = (mc, mp) => {
     val mct = mt(Z(mc.toString))
     val mpxi = mp.toString.reverse.toCharArray.map(_.asDigit).zipWithIndex.filter(_._1 != 0).map(_._2)
     mpxi.foldRight(Z("0"))((fi, sum) => sum + mct(fi)).z
   }
   //--- fd(dividend.z,divisor.z) ---------------------------
   val fd: (BigInt, BigInt) => BigInt = (dd, ds) => {
     val dst = dt(Z(dd.toString), Z(ds.toString)).reverse
     var diff = Z(dd.toString)
     val zd = ListBuffer[String]()
     0 until dst.length foreach { i =>
       if (dst(i) > diff) zd += "0" else {
         diff = diff - dst(i)
         zd += "1"
       }
     }
     BigInt(zd.mkString)
   }
   val fasig: (Z, Z) => Int = (z1, z2) => if (z1.z.abs > z2.z.abs) z1.z.signum else z2.z.signum
   val fssig: (Z, Z) => Int = (z1, z2) =>
     if ((z1.z.abs > z2.z.abs && z1.z.signum > 0) || (z1.z.abs < z2.z.abs && z1.z.signum < 0)) 1 else -1
   var z: BigInt = BigInt(zs)
   override def toString: String = "" + z + "Z(i:" + z2i(this) + ")"
   def size: Int = z.abs.toString.length
   def ++ : Z = {
     val za = this + Z("1")
     this.zs = za.zs
     this.z = za.z
     this
   }
   def +(that: Z): Z =
     if (this == Z("0")) that
     else if (that == Z("0")) this
     else if (this.z.signum == that.z.signum) Z((fa(this.z.abs.max(that.z.abs), this.z.abs.min(that.z.abs)) * this.z.signum).toString)
     else if (this.z.abs == that.z.abs) Z("0")
     else Z((fs(this.z.abs.max(that.z.abs), this.z.abs.min(that.z.abs)) * fasig(this, that)).toString)
   def -- : Z = {
     val zs = this - Z("1")
     this.zs = zs.zs
     this.z = zs.z
     this
   }
   def -(that: Z): Z =
     if (this == Z("0")) Z((that.z * (-1)).toString)
     else if (that == Z("0")) this
     else if (this.z.signum != that.z.signum) Z((fa(this.z.abs.max(that.z.abs), this.z.abs.min(that.z.abs)) * this.z.signum).toString)
     else if (this.z.abs == that.z.abs) Z("0")
     else Z((fs(this.z.abs.max(that.z.abs), this.z.abs.min(that.z.abs)) * fssig(this, that)).toString)
   def %(that: Z): Option[Z] =
     if (that == Z("0")) None
     else if (this == Z("0")) Some(Z("0"))
     else if (that == Z("1")) Some(Z("0"))
     else if (this.z.abs < that.z.abs) Some(this)
     else if (this.z == that.z) Some(Z("0"))
     else this / that match {
       case None => None
       case Some(z) => Some(this - z * that)
     }
   def *(that: Z): Z =
     if (this == Z("0") || that == Z("0")) Z("0")
     else if (this == Z("1")) that
     else if (that == Z("1")) this
     else Z((fm(this.z.abs.max(that.z.abs), this.z.abs.min(that.z.abs)) * this.z.signum * that.z.signum).toString)
   def /(that: Z): Option[Z] =
     if (that == Z("0")) None
     else if (this == Z("0")) Some(Z("0"))
     else if (that == Z("1")) Some(Z("1"))
     else if (this.z.abs < that.z.abs) Some(Z("0"))
     else if (this.z == that.z) Some(Z("1"))
     else Some(Z((fd(this.z.abs.max(that.z.abs), this.z.abs.min(that.z.abs)) * this.z.signum * that.z.signum).toString))
   def <(that: Z): Boolean = this.z < that.z
   def <=(that: Z): Boolean = this.z <= that.z
   def >(that: Z): Boolean = this.z > that.z
   def >=(that: Z): Boolean = this.z >= that.z
 }
 object Z {
   // only for comfort and result checking:
   val fibs: LazyList[BigInt] = {
     def series(i: BigInt, j: BigInt): LazyList[BigInt] = i #:: series(j, i + j)
     series(1, 0).tail.tail.tail
   }
   val z2i: Z => BigInt = z => z.z.abs.toString.toCharArray.map(_.asDigit).reverse.zipWithIndex.map { case (v, i) => v * fibs(i) }.foldRight(BigInt(0))(_ + _) * z.z.signum
   var fmts: Map[Z, List[Z]] = Map(Z("0") -> List[Z](Z("0"))) //map of Fibonacci multiples table of divisors
   // get division table (division weight vector)
   def dt(dd: Z, ds: Z): List[Z] = {
     val wv = new ListBuffer[Z]
     wv ++= mt(ds)
     var zs = ds.z.abs.toString
     val upper = dd.z.abs.toString
     while ((zs.length < upper.length)) {
       wv += (wv.toList.last + wv.toList.reverse.tail.head)
       zs = "1" + zs
     }
     wv.toList
   }
   // get multiply table from fmts
   def mt(z: Z): List[Z] = {
     fmts.getOrElse(z, Nil) match {
       case Nil =>
         val e = mwv(z)
         fmts = fmts + (z -> e)
         e
       case l => l
     }
   }
   // multiply weight vector
   def mwv(z: Z): List[Z] = {
     val wv = new ListBuffer[Z]
     wv += z
     wv += (z + z)
     var zs = "11"
     val upper = z.z.abs.toString
     while ((zs.length < upper.length)) {
       wv += (wv.toList.last + wv.toList.reverse.tail.head)
       zs = "1" + zs
     }
     wv.toList
   }
 }
 println("elapsed time: " + elapsed {
   calcs foreach { case (op1, op, op2) => println("" + op1 + " " + op + " " + op2 + " = "
     + {
     (ops(op)) (op1, op2) match {
       case None => None
       case Some(z) => z
       case z => z
     }
     }
     .ensuring { x =>
       (iops(op)) (z2i(op1), z2i(op2)) match {
         case None => None == x
         case Some(i) => i == z2i(x.asInstanceOf[Z])
         case i => i == z2i(x.asInstanceOf[Z])
       }
     })
   }
 } + " sec"
 )

} </lang> Output:

101Z(i:4) + 10100Z(i:11) = 100010Z(i:15)
101Z(i:4) - 10100Z(i:11) = -1010Z(i:-7)
101Z(i:4) * 10100Z(i:11) = 10010010Z(i:44)
101Z(i:4) / 10100Z(i:11) = 0Z(i:0)
-1010101Z(i:-33) + 10100Z(i:11) = -1000001Z(i:-22)
-1010101Z(i:-33) - 10100Z(i:11) = -10010010Z(i:-44)
-1010101Z(i:-33) * 10100Z(i:11) = -101010001010Z(i:-363)
-1010101Z(i:-33) / 10100Z(i:11) = -100Z(i:-3)
1000101010Z(i:109) + 10101010Z(i:54) = 10000101001Z(i:163)
1000101010Z(i:109) - 10101010Z(i:54) = 100000000Z(i:55)
1000101010Z(i:109) * 10101010Z(i:54) = 101000001000101001Z(i:5886)
1000101010Z(i:109) / 10101010Z(i:54) = 10Z(i:2)
10100Z(i:11) + 1010Z(i:7) = 101000Z(i:18)
100101Z(i:17) - 100Z(i:3) = 100001Z(i:14)
1010101010101010101Z(i:10945) + -1010101010101Z(i:-609) = 1010100000000000000Z(i:10336)
1010101010101010101Z(i:10945) - -1010101010101Z(i:-609) = 10000001010101010100Z(i:11554)
1010101010101010101Z(i:10945) * -1010101010101Z(i:-609) = -100010001000001001010010100100001Z(i:-6665505)
1010101010101010101Z(i:10945) / -1010101010101Z(i:-609) = -100101Z(i:-17)
1010101010101010101Z(i:10945) % -1010101010101Z(i:-609) = 1010100100100Z(i:592)
1010101010101010101Z(i:10945) + 101010101010101Z(i:1596) = 10000101010101010100Z(i:12541)
1010101010101010101Z(i:10945) - 101010101010101Z(i:1596) = 1010000000000000000Z(i:9349)
1010101010101010101Z(i:10945) * 101010101010101Z(i:1596) = 10001000100001010001001010001001001Z(i:17468220)
1010101010101010101Z(i:10945) / 101010101010101Z(i:1596) = 1001Z(i:6)
1010101010101010101Z(i:10945) % 101010101010101Z(i:1596) = 101000000001000Z(i:1369)
10101010101010101010Z(i:17710) + 1010101010101010Z(i:2583) = 100001010101010101001Z(i:20293)
10101010101010101010Z(i:17710) - 1010101010101010Z(i:2583) = 10100000000000000000Z(i:15127)
10101010101010101010Z(i:17710) * 1010101010101010Z(i:2583) = 1000100010001000000000001000100010001Z(i:45744930)
10101010101010101010Z(i:17710) / 1010101010101010Z(i:2583) = 1001Z(i:6)
10101010101010101010Z(i:17710) % 1010101010101010Z(i:2583) = 1010000000001000Z(i:2212)
1010Z(i:7) % 10Z(i:2) = 1Z(i:1)
1010Z(i:7) % -10Z(i:-2) = 1Z(i:1)
-1010Z(i:-7) % 10Z(i:2) = -1Z(i:-1)
-1010Z(i:-7) % -10Z(i:-2) = -1Z(i:-1)
100Z(i:3) / 0Z(i:0) = None
100Z(i:3) % 0Z(i:0) = None
elapsed time: 1 sec

Tcl

Translation of: Perl 6

<lang tcl>namespace eval zeckendorf {

   # Want to use alternate symbols? Change these
   variable zero "0"
   variable one "1"
   # Base operations: increment and decrement
   proc zincr var {

upvar 1 $var a namespace upvar [namespace current] zero 0 one 1 if {![regsub "$0$" $a $1$0 a]} {append a $1} while {[regsub "$0$1$1" $a "$1$0$0" a] || [regsub "^$1$1" $a "$1$0$0" a]} {} regsub ".$" $a "" a return $a

   }
   proc zdecr var {

upvar 1 $var a namespace upvar [namespace current] zero 0 one 1 regsub "^$0+(.+)$" [subst [regsub "${1}($0*)$" $a "$0\[ string repeat {$1$0} \[regsub -all .. {\\1} {} x]]\[ string repeat {$1} \[expr {\$x ne {}}]]"] ] {\1} a return $a

   }
   # Exported operations
   proc eq {a b} {

expr {$a eq $b}

   }
   proc add {a b} {

variable zero while {![eq $b $zero]} { zincr a zdecr b } return $a

   }
   proc sub {a b} {

variable zero while {![eq $b $zero]} { zdecr a zdecr b } return $a

   }
   proc mul {a b} {

variable zero variable one if {[eq $a $zero] || [eq $b $zero]} {return $zero} if {[eq $a $one]} {return $b} if {[eq $b $one]} {return $a} set c $a while {![eq [zdecr b] $zero]} { set c [add $c $a] } return $c

   }
   proc div {a b} {

variable zero variable one if {[eq $b $zero]} {error "div zero"} if {[eq $a $zero] || [eq $b $one]} {return $a} set r $zero while {![eq $a $zero]} { if {![eq $a [add [set a [sub $a $b]] $b]]} break zincr r } return $r

   }
   # Note that there aren't any ordering operations in this version
   # Assemble into a coherent API
   namespace export \[a-y\]*
   namespace ensemble create

}</lang> Demonstrating: <lang tcl>puts [zeckendorf add "10100" "1010"] puts [zeckendorf sub "10100" "1010"] puts [zeckendorf mul "10100" "1010"] puts [zeckendorf div "10100" "1010"] puts [zeckendorf div [zeckendorf mul "10100" "1010"] "1010"]</lang>

Output:
101000
101
101000001
1
10100

Visual Basic .NET

Translation of: C#

<lang vbnet>Imports System.Text

Module Module1

   Class Zeckendorf
       Implements IComparable(Of Zeckendorf)
       Private Shared ReadOnly dig As String() = {"00", "01", "10"}
       Private Shared ReadOnly dig1 As String() = {"", "1", "10"}
       Private dVal As Integer = 0
       Private dLen As Integer = 0
       Public Sub New(Optional x As String = "0")
           Dim q = 1
           Dim i = x.Length - 1
           dLen = i \ 2
           Dim z = Asc("0")
           While i >= 0
               Dim a = Asc(x(i))
               dVal += (a - z) * q
               q *= 2
               i -= 1
           End While
       End Sub
       Private Sub A(n As Integer)
           Dim i = n
           While True
               If dLen < i Then
                   dLen = i
               End If
               Dim j = (dVal >> (i * 2)) And 3
               If j = 0 OrElse j = 1 Then
                   Return
               ElseIf j = 2 Then
                   If ((dVal >> ((i + 1) * 2)) And 1) <> 1 Then
                       Return
                   End If
                   dVal += 1 << (i * 2 + 1)
                   Return
               ElseIf j = 3 Then
                   Dim temp = 3 << (i * 2)
                   temp = temp Xor -1
                   dVal = dVal And temp
                   B((i + 1) * 2)
               End If
               i += 1
           End While
       End Sub
       Private Sub B(pos As Integer)
           If pos = 0 Then
               Inc()
               Return
           End If
           If ((dVal >> pos) And 1) = 0 Then
               dVal += 1 << pos
               A(pos \ 2)
               If pos > 1 Then
                   A(pos \ 2 - 1)
               End If
           Else
               Dim temp = 1 << pos
               temp = temp Xor -1
               dVal = dVal And temp
               B(pos + 1)
               B(pos - If(pos > 1, 2, 1))
           End If
       End Sub
       Private Sub C(pos As Integer)
           If ((dVal >> pos) And 1) = 1 Then
               Dim temp = 1 << pos
               temp = temp Xor -1
               dVal = dVal And temp
               Return
           End If
           C(pos + 1)
           If pos > 0 Then
               B(pos - 1)
           Else
               Inc()
           End If
       End Sub
       Public Function Inc() As Zeckendorf
           dVal += 1
           A(0)
           Return Me
       End Function
       Public Function Copy() As Zeckendorf
           Dim z As New Zeckendorf With {
               .dVal = dVal,
               .dLen = dLen
           }
           Return z
       End Function
       Public Sub PlusAssign(other As Zeckendorf)
           Dim gn = 0
           While gn < (other.dLen + 1) * 2
               If ((other.dVal >> gn) And 1) = 1 Then
                   B(gn)
               End If
               gn += 1
           End While
       End Sub
       Public Sub MinusAssign(other As Zeckendorf)
           Dim gn = 0
           While gn < (other.dLen + 1) * 2
               If ((other.dVal >> gn) And 1) = 1 Then
                   C(gn)
               End If
               gn += 1
           End While
           While (((dVal >> dLen * 2) And 3) = 0) OrElse dLen = 0
               dLen -= 1
           End While
       End Sub
       Public Sub TimesAssign(other As Zeckendorf)
           Dim na = other.Copy
           Dim nb = other.Copy
           Dim nt As Zeckendorf
           Dim nr As New Zeckendorf
           Dim i = 0
           While i < (dLen + 1) * 2
               If ((dVal >> i) And 1) > 0 Then
                   nr.PlusAssign(nb)
               End If
               nt = nb.Copy
               nb.PlusAssign(na)
               na = nt.Copy
               i += 1
           End While
           dVal = nr.dVal
           dLen = nr.dLen
       End Sub
       Public Function CompareTo(other As Zeckendorf) As Integer Implements IComparable(Of Zeckendorf).CompareTo
           Return dVal.CompareTo(other.dVal)
       End Function
       Public Overrides Function ToString() As String
           If dVal = 0 Then
               Return "0"
           End If
           Dim idx = (dVal >> (dLen * 2)) And 3
           Dim sb As New StringBuilder(dig1(idx))
           Dim i = dLen - 1
           While i >= 0
               idx = (dVal >> (i * 2)) And 3
               sb.Append(dig(idx))
               i -= 1
           End While
           Return sb.ToString
       End Function
   End Class
   Sub Main()
       Console.WriteLine("Addition:")
       Dim g As New Zeckendorf("10")
       g.PlusAssign(New Zeckendorf("10"))
       Console.WriteLine(g)
       g.PlusAssign(New Zeckendorf("10"))
       Console.WriteLine(g)
       g.PlusAssign(New Zeckendorf("1001"))
       Console.WriteLine(g)
       g.PlusAssign(New Zeckendorf("1000"))
       Console.WriteLine(g)
       g.PlusAssign(New Zeckendorf("10101"))
       Console.WriteLine(g)
       Console.WriteLine()
       Console.WriteLine("Subtraction:")
       g = New Zeckendorf("1000")
       g.MinusAssign(New Zeckendorf("101"))
       Console.WriteLine(g)
       g = New Zeckendorf("10101010")
       g.MinusAssign(New Zeckendorf("1010101"))
       Console.WriteLine(g)
       Console.WriteLine()
       Console.WriteLine("Multiplication:")
       g = New Zeckendorf("1001")
       g.TimesAssign(New Zeckendorf("101"))
       Console.WriteLine(g)
       g = New Zeckendorf("101010")
       g.PlusAssign(New Zeckendorf("101"))
       Console.WriteLine(g)
   End Sub

End Module</lang>

Output:
Addition:
101
1001
10101
100101
1010000

Subtraction:
1
1000000

Multiplication:
1000100
1000100