/* 
  an example from llreve:
  http://formal.iti.kit.edu/projects/improve/reve/
*/

int f1(int n) {
  int r;
  r = 0;

  if (n <= 1) {
    r = n;
  } else {
    r = f1(n - 1);
    r = n + r;
  }

  return r;
}

int f2(int n) {
  int r;
  r = 0;

  if (n <= 1) {
    r = n;
  } else {
    r = f2(n - 3);
    r = n + (n-1) + r;
  }

  return r;
}
