--- pl:prolog:pllib:union [2019/06/27 15:50]
+++ pl:prolog:pllib:union [2019/06/27 15:50] (aktualna)
@@ Linia 1: / Linia 1: @@
+====== Union ======
+{{tag>lists}}
+===== Description =====
+Finding the union of two lists
+**Source**:  The Art of Prolog
+===== Download =====
+Program source code: {{union.pl}}
+===== Listing =====
+<code prolog>
+/*
+   union(Xs,Ys,Us) :- Us is the union of the elements in Xs and Ys.
+*/
+union([X|Xs],Ys,Us) :- member(X,Ys), union(Xs,Ys,Us).
+union([X|Xs],Ys,[X|Us]) :- nonmember(X,Ys), union(Xs,Ys,Us).
+union([],Ys,Ys).
+/*
+   nonmember(X,Xs) :- X is not a member of the list Xs.
+*/
+     nonmember(X,[Y|Ys]) :- X \== Y, nonmember(X,Ys).
+     nonmember(X,[]).
+%  Program 13.1    Finding the union of two lists
+</code>
+===== Comments =====

pl/prolog/pllib/union.txt · ostatnio zmienione: 2019/06/27 15:50 (edycja zewnętrzna)

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