====== Permutation ======
{{tag>lists}}
===== Description =====
A procedure calculates permutaion of the list.

**Source**:  Guide to Prolog Programming (on-line tutorial)
===== Download =====
Program source code: {{permutation.pl}}
===== Listing =====
<code prolog>
perm(List,[H|Perm]):-delete(H,List,Rest),perm(Rest,Perm).
perm([],[]).
   
delete(X,[X|T],T).
delete(X,[H|T],[H|NT]):-delete(X,T,NT).</code>
===== Comments =====