extern void __VERIFIER_error() __attribute__ ((__noreturn__)); extern char __VERIFIER_nondet_char(void); void __VERIFIER_assert(int cond) { if (!(cond)) { ERROR: __VERIFIER_error(); } return; } signed char gcd_test(signed char a, signed char b) { signed char t; if (a < (signed char)0) a = -a; if (b < (signed char)0) b = -b; while (b != (signed char)0) { t = b; b = a % b; a = t; } return a; } int main() { signed char x = __VERIFIER_nondet_char(); signed char y = __VERIFIER_nondet_char(); signed char g; g = gcd_test(x, y); if (y > (signed char)0) { __VERIFIER_assert(y >= g); } return 0; }