Consider a subroutine swap that takes two parameters and simply swaps their values. For example, after calling swap (X, Y), X should have the original value of Y and Y the original value of X. Assume that variables to be swapped can be simple or subscripted (elements of an array), and they have the same type (integer). Show that it is impossible to write such a general-purpose swap subroutine in a language with: (a) parameter passing by value.
(b) parameter passing by name
Hint: for the case of passing by name, consider mutually dependent parameters.