====== Sets sum ======
{{tag>set_algebra lists}}
===== Description =====
Showing how to find sum of two sets

**Source**:  PROLOG str. 190 Wydawnictwo PLJ Warszawa 1991 ISBN 83-85190-63-5
===== Download =====
Program source code: {{sets_sum.pl}}
===== Listing =====
<code prolog>
suma([], X, X).
suma([X|R], Y, Z) :- member(X, Y), !, suma(R, Y, Z).
suma([X|R], Y, [X|Z]) :- suma(R, Y, Z).

test :- suma([1, 2, 3], [2, 4], C).</code>
===== Comments =====