void abort() { };
                                                                                                                                                          
                                                                               

/*@ 
    requires ((1 <= cond)) && (cond != 0);
    ensures ((1 <= cond)) && (1);
@*/
void __VERIFIER_assert(int cond) {
  if (!(cond)) {
    ERROR: {/*@ assert(0); */;abort();}
  }
  return;
}

/*@ 
    requires (1);
    ensures ((((z % 2) != 0) || ((\result % 2) == 0)));
@*/
unsigned int f(unsigned int z) {
  return z + 2;
}

int main() {
  unsigned int x = 0;

/*@
loop invariant (((x % 2) == 0));
@*/
  while (x < 0x0fffffff) {
    x = f(x);
  }

  __VERIFIER_assert(!(x % 2));
}