// verifast_options{disable_overflow_check target:ILP32} /* Geometric Series computes x = sum(z^k)[k=0..k-1], y = z^(k-1) */ extern void abort(void); //@ requires integer(&counter, ?veri_req_counter) &*& true; //@ ensures integer(&counter, ?veri_ens_counter) &*& true; void reach_error() //@ requires false; //@ ensures true; {}extern int __VERIFIER_nondet_int(void); //@ requires integer(&counter, ?veri_req_counter) &*& true; //@ ensures integer(&counter, ?veri_ens_counter) &*& true; void assume_abort_if_not(int cond) //@ requires integer(&counter, ?veri_req_counter) &*& true; //@ ensures integer(&counter, ?veri_ens_counter) &*& true; { if(!cond) {abort();} } void __VERIFIER_assert(int cond) //@ requires integer(&counter, ?veri_req_counter) &*& (1 <= cond); //@ ensures integer(&counter, ?veri_ens_counter) &*& (1 <= cond); { if (!(cond)) { ERROR: {reach_error();} } return; } int counter = 0; int main() //@ requires module(geo2_ll_unwindbound1__verifast_instrumented, true) &*& (counter == 0); //@ ensures (counter == 0) &*& junk(); { //@ open_module(); int z, k; unsigned long long x, y, c; z = __VERIFIER_nondet_int(); k = __VERIFIER_nondet_int(); x = 1; y = 1; c = 1; while (counter++<1) //@ invariant integer(&counter, ?veri_inv_counter) &*& (((((y == 1) && (x == 1)) && (veri_inv_counter == 0)) || (((z == y) && (1 <= veri_inv_counter)) && (x == (z + 1)))) && (veri_req_counter == 0)); { __VERIFIER_assert(1 + x*z - x - z*y == 0); if (!(c < k)) break; c = c + 1; x = x * z + 1; y = y * z; } __VERIFIER_assert(1 + x*z - x - z*y == 0); return 0; }