User:Thebigh/mysandbox: Difference between revisions
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Given the number 1 as input the following program will, as its (3n-2)th step, produce the number 2^n. |
Given the number 1 as input the following program will, as its (3n-2)th step, produce the number 2^n. |
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<lang fractran> {2/3, 9/2, 2/1}</lang> |
<lang fractran> {2/3, 9/2, 2/1}</lang> |
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==Logical operations== |
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It's not so hard to code up all sixteen possible two-input logic gates, so here they are. The input is 2^a 3^b where a,b are zero or one and the output is 5^1 for true and 5^0 for false. Gates that return true when all their inputs are false additionally require the flag 11 to be set as input (ie 2^a*3^b*11)- any FRACTRAN program with the number 1 as input either stops without doing anything or loops forever. |
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<lang fractran> |
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{5/6, 1/2, 1/3} AND gate |
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{5/6, 5/2, 5/3} OR gate |
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{1/22, 5/11} NOT gate (uses 11 as a halt flag, result of 2^a*11 is 5^not(a)) |
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{1/6, 5/2, 5/3} XOR gate |
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{1/66, 5/22, 5/33, 5/11} NAND gate (needs 11 flag) |
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{5/66, 1/22, 1/33, 5/11} NXOR gate (needs flag) |
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{1/66, 1/22, 1/33, 5/11} NOR gate (needs flag) |
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so much for all the commonly encountered ones, but there's still another ten to go |
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{1/2, 1/3} ZERO gate, returns false regardless of its input |
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</lang> |
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==Sort three variables== |
==Sort three variables== |
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Revision as of 16:31, 23 November 2021
Some FRACTRAN programs in case we ever have a category for it
A+B
Input a number of the form 2^a 3^b <lang fractran> {2/3} </lang> The output is 2^(a+b)
Empty program
A list of no fractions does nothing, then immediately stops. <lang fractran>{}</lang>
Integer Sequence
Given the number 1 as input the following program will, as its (3n-2)th step, produce the number 2^n. <lang fractran> {2/3, 9/2, 2/1}</lang>
Logical operations
It's not so hard to code up all sixteen possible two-input logic gates, so here they are. The input is 2^a 3^b where a,b are zero or one and the output is 5^1 for true and 5^0 for false. Gates that return true when all their inputs are false additionally require the flag 11 to be set as input (ie 2^a*3^b*11)- any FRACTRAN program with the number 1 as input either stops without doing anything or loops forever.
<lang fractran> {5/6, 1/2, 1/3} AND gate {5/6, 5/2, 5/3} OR gate {1/22, 5/11} NOT gate (uses 11 as a halt flag, result of 2^a*11 is 5^not(a)) {1/6, 5/2, 5/3} XOR gate {1/66, 5/22, 5/33, 5/11} NAND gate (needs 11 flag) {5/66, 1/22, 1/33, 5/11} NXOR gate (needs flag) {1/66, 1/22, 1/33, 5/11} NOR gate (needs flag)
so much for all the commonly encountered ones, but there's still another ten to go
{1/2, 1/3} ZERO gate, returns false regardless of its input </lang>
Sort three variables
FRACTRAN's only data type is positive integers. Suppose (a,b,c) are the integers to be sorted. Give the following as input: 2^a 3^b 5^c <lang fractran> {1001/30, 143/6, 143/10, 143/15, 13/2, 13/3, 13/5} </lang> Returns 7^A 11^B 13^C where (A,B,C) are (a,b,c) in ascending order.