for statement
int
fib_pure_iter(int n) {
n int a = 1;
n int b = 0;
n int old_a = 1;
n
for (int i = 0; i < n; i = i + 1)
{
old_a = a;
a = a + b;
b = old_a;
n }
n return b;
n}
n
Counter oriented
for (counter decl ; test ; incrs) stmt ;