diff --git a/C/eval.c b/C/eval.c
index 38144c5b6..5eb1667ee 100644
--- a/C/eval.c
+++ b/C/eval.c
@@ -97,7 +97,6 @@ Eval(Term t USES_REGS)
 {
 
   if (IsVarTerm(t)) {
-    LOCAL_ArithError = TRUE;
     return Yap_ArithError(INSTANTIATION_ERROR,t,"in arithmetic");
   } else if (IsNumTerm(t)) {
     return t;
@@ -220,7 +219,7 @@ X is 2+3*4
 static Int
 p_is( USES_REGS1 )
 {				/* X is Y	 */
-  Term out = 0L;
+  Term out;
   yap_error_number err;
 
   Term t = Deref(ARG2);
@@ -241,7 +240,7 @@ p_is( USES_REGS1 )
       }
     } else {
       Yap_EvalError(err, ARG2, "X is Exp");
-    return FALSE;
+      return FALSE;
     }
   } while (TRUE);
   return Yap_unify_constant(ARG1,out);
diff --git a/C/stdpreds.c b/C/stdpreds.c
index ad1169c52..dbc457297 100644
--- a/C/stdpreds.c
+++ b/C/stdpreds.c
@@ -606,22 +606,35 @@ p_univ( USES_REGS1 )
     }
     if (IsNumTerm(twork)) {
       Term tt = TailOfTerm(t2);
-      if (IsVarTerm(tt) || tt != MkAtomTerm(AtomNil)) {
+      if (IsVarTerm(tt)) {
+	Yap_Error(INSTANTIATION_ERROR, tt, "(=..)/2");
+	return (FALSE);
+      }
+      if ( tt != MkAtomTerm(AtomNil)) {
 	Yap_Error(TYPE_ERROR_ATOMIC, twork, "(=..)/2");
 	return (FALSE);
       }
       return (Yap_unify_constant(ARG1, twork));
     }
     if (!IsAtomTerm(twork)) {
-      Yap_Error(TYPE_ERROR_ATOMIC, twork, "(=..)/2");
-      return (FALSE);
+      Term tt = TailOfTerm(t2);
+      if (IsVarTerm(tt)) {
+	Yap_Error(INSTANTIATION_ERROR, twork, "(=..)/2");
+	return(FALSE);
+      } else if (tt == MkAtomTerm(AtomNil)) {
+	Yap_Error(TYPE_ERROR_ATOMIC, twork, "(=..)/2");
+	return (FALSE);
+      } else {
+	Yap_Error(TYPE_ERROR_ATOM, twork, "(=..)/2");
+	return (FALSE);
+      }
     }      
     at = AtomOfTerm(twork);
     twork = TailOfTerm(t2);
     if (IsVarTerm(twork)) {
       Yap_Error(INSTANTIATION_ERROR, twork, "(=..)/2");
       return(FALSE);
-    } else if (!IsPairTerm(twork)) {
+    } else  if (!IsPairTerm(twork)) {
       if (twork != TermNil) {
 	Yap_Error(TYPE_ERROR_LIST, ARG2, "(=..)/2");
 	return(FALSE);