don't have a single main stack.
\begin{code}
-#if !defined(PAR) /* && !defined(GRAN) */ /* HWL */
+#if !defined(PAR)
void
EvacuateAStack(PP_ stackA, PP_ botA /* botA points to bottom-most word */)
{
Otherwise closure is live update reference to to-space address
\begin{code}
-#if !defined(PAR) /* && !defined(GRAN) */ /* HWL */
+#if !defined(PAR)
void
EvacuateBStack( stackB, botB, roots )
P_ stackB;