Problem 4

Give examples to show that , NAND, and NOR are not associative. Problem 5

A Boolean function f does not depend on the first argument if f(TRUE, x2, x3, ..., xk) = f(FALSE, x2, x3, ..., xk)

for any truth values x2,x3,...,xk. Similarly, we can say f does not depend on its ith argument if the value of f never changes when its ith argument is switched between TRUE and FALSE. How many Boolean functions of two arguments do not depend on their first or second argument (or both)?