Semordnilap
Arturo
<lang rebol>words: read.lines "http://wiki.puzzlers.org/pub/wordlists/unixdict.txt" pairs: [] loop words 'wrd [
if and? contains? words reverse wrd wrd <> reverse wrd [ 'pairs ++ @[@[wrd reverse wrd]] print [wrd "-" reverse wrd] ]
]
unique 'pairs
print map 1..5 => [sample pairs]</lang>