void abort() { }; extern int __VERIFIER_nondet_int(); /*@ requires (1); ensures ((cond != 0)); @*/ void assume_abort_if_not(int cond) { if(!cond) {abort();} } /*@ requires ((1 <= cond)) && (cond != 0); ensures ((1 <= cond)) && (1); @*/ void __VERIFIER_assert(int cond) { if (!(cond)) { ERROR: {/*@ assert(0); */;} } return; } int main() { int x, y; long long a, b, p, q, r, s, c, k, xy, yy; x = __VERIFIER_nondet_int(); assume_abort_if_not(x>=0 && x<=2); y = __VERIFIER_nondet_int(); assume_abort_if_not(y>=0 && y<=2); assume_abort_if_not(x >= 1); assume_abort_if_not(y >= 1); a = x; b = y; p = 1; q = 0; r = 0; s = 1; c = 0; k = 0; xy = (long long) x * y; yy = (long long) y * y; assume_abort_if_not(xy < 2147483647); assume_abort_if_not(yy < 2147483647); /*@ loop invariant ((((((((((((((b == 1) && (s == 0)) && (p == 0)) && (y == xy)) && (r == 1)) && (a == y)) && (x == 1)) && (yy == ((long long) y * y))) && (a == 2)) && (q == 1)) || (((((((((1 <= x) && (y <= 2)) && (b == 0)) && (p == 0)) && (r == 1)) && (a == y)) && (1 <= y)) && ((((__int128) q * x) + ((__int128) y * s)) == 0)) && (x <= 2))) || ((((((((((((r == 0) && (y <= 2)) && (s == 1)) && (1 <= a)) && (b == y)) && (yy == ((long long) y * y))) && (q == 0)) && (1 <= y)) && (xy == ((long long) y * x))) && (a == x)) && (x <= 2)) && (p == 1))) || (((((((((((long long) x + 1) <= y) && (r == 0)) && (((__int128) ((long long) x * 2) + b) == y)) && (y <= 2)) && (s == 1)) && (((__int128) q + 2) == 0)) && (((__int128) b + 1) <= x)) && (a == x)) && (p == 1)))); @*/ while (1) { if (!(b != 0)) break; c = a; k = 0; /*@ loop invariant (((((((((((((((((((r == 0) && (s == 1)) && (a == ((__int128) c + b))) && (0 <= c)) && (b == y)) && (k == 1)) && (yy == ((long long) y * y))) && (q == 0)) && (1 <= y)) && (xy == ((long long) y * x))) && (a == x)) && (x <= 2)) && (p == 1)) || ((((((((((((((r == 0) && (a == (c + ((__int128) b * k)))) && (s == 1)) && (1 <= a)) && (0 <= c)) && (yy == ((long long) y * y))) && ((c + ((__int128) b * 2)) <= 2)) && (q == 0)) && (1 <= b)) && (xy == ((long long) y * x))) && (a == x)) && (x == (c + ((__int128) k * y)))) && (x <= 2)) && (p == 1))) || ((((((((((((((r == 0) && (y <= 2)) && (k == 0)) && (s == 1)) && (1 <= a)) && (b == y)) && (yy == ((long long) y * y))) && (q == 0)) && (1 <= y)) && (xy == ((long long) y * x))) && (a == x)) && (c == x)) && (x <= 2)) && (p == 1))) || ((((((((((((y == 2) && (b == 1)) && (s == 0)) && (p == 0)) && (k == 0)) && (2 == xy)) && (r == 1)) && (c == 2)) && (x == 1)) && (yy == 4)) && (a == 2)) && (q == 1))) || ((((((((((((y == 2) && (b == 1)) && (s == 0)) && (p == 0)) && (2 == xy)) && (r == 1)) && (x == 1)) && (yy == 4)) && (k == 1)) && (a == 2)) && (q == 1)) && (c == 1))) || ((((((((((((y == 2) && (b == 1)) && (s == 0)) && (p == 0)) && (2 == xy)) && (r == 1)) && (x == 1)) && (yy == 4)) && (k == 2)) && (a == 2)) && (c == 0)) && (q == 1)))); @*/ while (1) { __VERIFIER_assert(a == k * b + c); __VERIFIER_assert(a == y*r + x*p); __VERIFIER_assert(b == x * q + y * s); __VERIFIER_assert(q*xy + s*yy - q*x - b*y - s*y + b == 0); if (!(c >= b)) break; c = c - b; k = k + 1; } a = b; b = c; long long temp; temp = p; p = q; q = temp - q * k; temp = r; r = s; s = temp - s * k; } __VERIFIER_assert(q*x + s*y == 0); __VERIFIER_assert(p*x + r*y == a); return a; }