above activation address also amount ar base because below blank call called calls case clone code consider data definition equation equations example executing factorial fib fibonacci first following i.e induction infinite informal int iterative just k1 k2 k3 less let's line linked list little made main make makes marker mathematical memory method methods must n+1 n-1 note parameter print printchar printint problem program prove recurrence recursion recursive result return returns rule runtime second simpler size slower solution stack statement static string system.out.println system.out.println(k t(0 t(n test think time times tmp total use using usually value values version void way work