--- ray/src/common/calexpr.c	1991/04/17 10:54:58	1.8
+++ ray/src/common/calexpr.c	1991/04/23 16:56:39	1.11
@@ -78,8 +78,10 @@ double  (*eoper[])() = {		/* expression operations */
 	esubtr,
 	0,
 	edivi,
-	0,0,0,0,0,0,0,0,0,0,0,0,0,
+	0,0,0,0,0,0,0,0,0,0,
 	ebotch,
+	0,0,
+	ebotch,
 	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
 	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
 	epow,
@@ -641,6 +643,10 @@ getE5()				/* E5 -> (E1) */
 	    syntax("'(' expected");
 #endif
 #endif
+#ifdef  RCONST
+	if (isconstvar(ep1))
+	    ep1 = rconst(ep1);
+#endif
 	return(ep1);
     }
 #endif
@@ -672,4 +678,57 @@ register EPNODE  *epar;
  
     return(ep);
 }
+
+
+isconstvar(ep)			/* is ep linked to a constant expression? */
+register EPNODE  *ep;
+{
+#ifdef  VARIABLE
+    register EPNODE  *ep1;
+#ifdef  FUNCTION
+
+    if (ep->type == FUNC) {
+	if (!isconstfun(ep->v.kid))
+		return(0);
+	for (ep1 = ep->v.kid->sibling; ep1 != NULL; ep1 = ep1->sibling)
+	    if (ep1->type != NUM && !isconstfun(ep1))
+		return(0);
+	return(1);
+    }
+#endif
+    if (ep->type != VAR)
+	return(0);
+    ep1 = ep->v.ln->def;
+    if (ep1 == NULL || ep1->type != ':')
+	return(0);
+#ifdef  FUNCTION
+    if (ep1->v.kid->type != SYM)
+	return(0);
+#endif
+    return(1);
+#else
+    return(ep->type == FUNC);
+#endif
+}
+
+
+#if  defined(FUNCTION) && defined(VARIABLE)
+isconstfun(ep)			/* is ep linked to a constant function? */
+register EPNODE  *ep;
+{
+    register EPNODE  *dp;
+    register LIBR  *lp;
+
+    if (ep->type != VAR)
+	return(0);
+    dp = ep->v.ln->def;
+    if (dp != NULL && dp->type != ':')
+	return(0);
+    if ((dp == NULL || dp->v.kid->type != FUNC)
+	    && ((lp = liblookup(ep->v.ln->name)) == NULL
+		    || lp->atyp != ':'))
+	return(0);
+    return(1);
+}
+#endif
 #endif