====== Combinations without repeated ======
{{tag>combinatorics}}
===== Description =====
Program calculates combinations without repeated elements.

**Source**:  Guide to Prolog Programming (on-line tutorial)
===== Download =====
Program source code: {{combinations_without_repeated.pl}}
===== Listing =====
<code prolog>
comb2(_,[]).
comb2([X|T],[X|Comb]):-comb2(T,Comb).
comb2([_|T],[X|Comb]):-comb2(T,[X|Comb]).


% use ?-comb2([1,2,3,4],[X,Y]) to generate combinations with two elements.</code>
===== Comments =====