:- module(leq,[leq/2]). :- use_module(library(chr)). :- chr_constraint leq/2. reflexivity @ leq(X,X) <=> true. antisymmetry @ leq(X,Y), leq(Y,X) <=> X = Y. idempotence @ leq(X,Y) \ leq(X,Y) <=> true. transitivity @ leq(X,Y), leq(Y,Z) ==> leq(X,Z). |
:- module(dom,[dom/2]). :- use_module(library(chr)). :- chr_constraint dom(?int,+list(int)). :- chr_type list(T) ---> [] ; [T|list(T)]. dom(X,[]) <=> fail. dom(X,[Y]) <=> X = Y. dom(X,L) <=> nonvar(X) | memberchk(X,L). dom(X,L1), dom(X,L2) <=> intersection(L1,L2,L3), dom(X,L3). |