Correctness of recursive methods
However, to understand that a particular recursive method is correct, you should not think about executing it. Rather, do two things:
Understand that each recursive method call is correct in terms of the specification of the method.
Make sure that the recursion �terminates� (much like making sure that a loop terminates). That is, see to it that in some sense the arguments of the recursive call are �smaller� than the parameters of the method and that when the parameters are �as small as possible�, the method terminates without calling itself recursively. We�ll see this in the examples.