From: Mark Thom <markjordanthom@gmail.com>
Date: Mon, 4 Mar 2019 01:14:05 +0000 (-0700)
Subject: remove unification from dif/2
X-Git-Tag: v0.8.110~214
X-Git-Url: https://git.sagredo.dev/?a=commitdiff_plain;h=f458d1267637c5824e6a0e8fc07dcd0ad0a01af3;p=scryer-prolog.git

remove unification from dif/2
---

diff --git a/src/prolog/lib/dif.pl b/src/prolog/lib/dif.pl
index 72101b82..e830a206 100644
--- a/src/prolog/lib/dif.pl
+++ b/src/prolog/lib/dif.pl
@@ -37,8 +37,7 @@ verify_attributes(Var, Value, Goals) :-
 % suggestions for improvement.
 
 dif(X, Y) :- X \== Y,
-             (   X \= Y -> true
-	     ;   term_variables(X, XVars), term_variables(Y, YVars),
+             (   term_variables(X, XVars), term_variables(Y, YVars),
 	         dif_set_variables(XVars, X, Y),
 		 dif_set_variables(YVars, X, Y)
 	     ).