From Modern programming languages : a practical introduction 2nd

Exercise 7 For each of the following ML functions, could the activation record for the function be deallocated as soon as the function returns? Explain why or why not.

a. fun f x = x + 1;

b. fun f x = fn y => x + y;

c. fun f x = fn y => y + 1;

d. fun f x = map - x;