ACTUALLY DRAW THE STACK

Show the stack with all activation record instances, including static and

dynamic chains, when execution reaches position $1$ in the following

skeletal program. Assume bigsub is at level $1.$

function bigsub$()\{$

var mysum;

function a$()\{$

var x;

function b$($sum$)\{$

var y$,$ z;

$...$

c$($z$)$;

$...$

$\}//$ end of b

$...$

b$($x$)$;

$...$

$\}//$ end of a

function c$($plums$)\{$

$\}//$ end of c

var l;

$...$

a$()$;

$...$

$\}//$ end of bigsub