Suppose that we implement the functions of Figure using a display. Show the display at the moment the first call to fib0(1) is about to return. Also, indicate the saved display entry in each of the activation records on the stack at that time.
Given is : Nested functions computing Fibonacci numbers
fun main 0 {
let
fun fib0(n)=
let
fun fib1(n) =
let
fun fib2(n) = fib1(n-1) + fib1(n-2)
in
if n >= 4 then fib2(n)
else fib0(n-1) + fib0(n-2)
end
in
if n >= 2 then fib1(n)
else 1
end
in
fib0(4)
end;