--- ray/src/common/caldefn.c	1995/02/16 09:49:27	2.7
+++ ray/src/common/caldefn.c	1995/03/28 11:18:52	2.9
@@ -42,7 +42,7 @@ extern char  *ecalloc(), *emalloc(), *savestr(), *strc
 
 static double  dvalue();
 
-long  eclock = -1;			/* value storage timer */
+unsigned long  eclock = 0;		/* value storage timer */
 
 static char  context[MAXWORD+1];	/* current context path */
 
@@ -299,6 +299,8 @@ toolong:
 incontext(qn)			/* is qualified name in current context? */
 register char  *qn;
 {
+    if (!context[0])			/* global context accepts all */
+	return(1);
     while (*qn && *qn != CNTXMARK)	/* find context mark */
 	qn++;
     return(!strcmp(qn, context));
@@ -327,7 +329,7 @@ int  lvl;
 				/* if context is global, clear all */
     for (i = 0; i < NHASH; i++)
 	for (vp = hashtbl[i]; vp != NULL; vp = vp->next)
-	    if (!context[0] || incontext(vp->name))
+	    if (incontext(vp->name))
 		if (lvl >= 2)
 		    dremove(vp->name);
 		else
@@ -638,7 +640,7 @@ getdefn()			/* A -> SYM = E1 */
 	    ep1->sibling->type != NUM) {
 	ep1 = newnode();
 	ep1->type = TICK;
-	ep1->v.tick = -1;
+	ep1->v.tick = 0;
 	addekid(ep2, ep1);
 	ep1 = newnode();
 	ep1->type = NUM;
@@ -699,8 +701,8 @@ EPNODE	*d;
     if (ep1->type == NUM)
 	return(ep1->v.num);			/* return if number */
     ep2 = ep1->sibling;				/* check time */
-    if (ep2->v.tick < 0 || ep2->v.tick < eclock) {
-	ep2->v.tick = d->type == ':' ? 1L<<30 : eclock;
+    if (ep2->v.tick == 0 || ep2->v.tick < eclock) {
+	ep2->v.tick = d->type == ':' ? ~0L : eclock;
 	ep2 = ep2->sibling;
 	ep2->v.num = evalue(ep1);		/* needs new value */
     } else