// verifast_options{disable_overflow_check target:ILP32}


extern void abort(void);
//@ requires true;
//@ ensures true;
void reach_error()
//@ requires false;
//@ ensures true;
{}void __VERIFIER_assert(int cond) 
//@ requires (cond != 0);
//@ ensures (cond != 0);
{ if(!(cond)) { ERROR: {reach_error();abort();} } }extern bool __VERIFIER_nondet_bool();
//@ requires true;
//@ ensures true;
int main() 
//@ requires module(mine2017_ex4_8__verifast_instrumented, true);
//@ ensures junk();
{
    //@ open_module(); 
  int v = 0;
while (__VERIFIER_nondet_bool() == 0)
//@ invariant ((v <= 1) && (0 <= v));
    {
    __VERIFIER_assert(0 <= v);
    __VERIFIER_assert(v <= 1);
    if (v == 0)
      v = 1;
  }
  return 0;
}