--- pl:prolog:pllib:variables_in_term [2019/06/27 15:50]
+++ pl:prolog:pllib:variables_in_term [2019/06/27 15:50] (aktualna)
@@ Linia 1: / Linia 1: @@
+====== Variables in term ======
+{{tag>predicates}}
+===== Description =====
+Numbering the variables in a term
+**Source**:  The Art of Prolog
+===== Download =====
+Program source code: {{variables_in_term.pl}}
+===== Listing =====
+<code prolog>
+/*
+   numbervars(Term,N1,N2) :-
+	The variables in Term are numbered from N1 to N2-1.
+*/
+	numbervars('$VAR'(N),N,N1) :- N1 is N+1.
+	numbervars(Term,N1,N2) :-
+	   nonvar(Term), functor(Term,Name,N), numbervars(0,N,Term,N1,N2).
+	numbervars(N,N,Term,N1,N1).
+	numbervars(I,N,Term,N1,N3) :-
+		I < N,
+		I1 is I+1,
+		arg(I1,Term,Arg),
+		numbervars(Arg,N1,N2),
+		numbervars(I1,N,Term,N2,N3).
+%  Program 10.8: Numbering the variables in a term
+</code>
+===== Comments =====

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

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