====== Variation 2 ======
{{tag>combinatorics lists}}
===== Description =====
Program create variation with repeated list elements

**Source**:  Guide to Prolog Programming (on-line tutorial)
===== Download =====
Program source code: {{variation_2.pl}}
===== Listing =====
<code prolog>
varia_rep(0,_,[]).
varia_rep(N,L,[H|RVaria]):-N>0,N1 is N-1,delete(H,L,_),varia_rep(N1,L,RVaria).

delete(X,[X|T],T).
delete(X,[H|T],[H|NT]):-delete(X,T,NT).</code>
===== Comments =====