contract C { function f(int8 x) public pure returns (int8) { x = -2; int8 y; unchecked { y = x - 127; } assert(y == 127); x = -128; unchecked { y = x - 127; } assert(y == 1); x = 127; unchecked { y = x - (-127); } assert(y == -2); return y; } } // ==== // SMTEngine: all // ---- // Info 1391: CHC: 3 verification condition(s) proved safe! Enable the model checker option "show proved safe" to see all of them.