BEFORE CALLING func2:

main
	x <- 6

-----------------
DURING CALL:

main
	x <- 6

func2
	x <- 9

-----------------
ON RETURN:

main
	x <- 6

==================
BEFORE CALLING func3:

main
	x <- 6
	y <- 21

-----------------
DURING CALL:

main
	x <- 6
	y <- 21

func3 : y <- 21, then 3456


-----------------
ON RETURN:

main
	x <- 6
	y <- 21