Friday's Exercises

Exercise 1:

Write a procedure that will multiply two numbers together, but the
only arithmetic operation allowed is addition (ie multiplication
through repeated addition).
(slow-mul 3 4) -> 12

Exercise 2:

Write a procedure that infinite loops.  [Save first!] (MITScheme
users, Ctrl-C Ctrl-C will break out of an infinite loop)
(loop) -> ...........

Exercise 3:

Write a procedure that computes the number of decimal digits in it's
input.
(num-digits 102) -> 3