From a1022f8237b5928ce68bb25c729ad4b74a9d1b51 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=ADtor=20Santos=20Costa?= <vsc@dcc.fc.up.pt>
Date: Thu, 2 Oct 2014 14:32:26 +0100
Subject: [PATCH] always deref arguments to built-ins.

---
 C/cmppreds.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/C/cmppreds.c b/C/cmppreds.c
index 693d33f00..700623699 100644
--- a/C/cmppreds.c
+++ b/C/cmppreds.c
@@ -794,7 +794,9 @@ a_eq(Term t1, Term t2)
 {
   CACHE_REGS
   /* A =:= B		 */
-  int out;
+  Int out;
+  t1 = Deref(t1);
+  t2 = Deref(t2);
 
   if (IsVarTerm(t1)) {
     Yap_Error(INSTANTIATION_ERROR, t1, "=:=/2");