Consider the following piece of code written in a pseudo$-$language using static

scope and call by reference $($see Sect. $7\mathrm{.}1\mathrm{.}2)$:

$\{$int $x=0$;

int $A($reference int $y\{$

int $x=2$;

$y=y+1$;

return $B(y)+x$;

$\}$

int $B($reference int $y$

int $C($reference int $y)\{$

int $x=3$;

return $A(y)+x+y$;

$\}$

if $(y==1)$ return $C(x)+y$;

else return $x+y$;

$\}$

write $(A(x))$;

$\}$

Assume that static scope is implemented using a display. Draw a diagram show$-$

ing the state of the display and the activation$-$record stack when control enters

the function A for the second time. For every activation record, just give value

for the field that saves the previous value of the display.