leq.chr

:- module(order, [leq/2]).
:- 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).