pragma experimental SMTChecker; contract C { function f(int8 x) public pure returns (int8) { x = -2; int8 y = x - 127; assert(y == 127); x = -128; y = x - 127; assert(y == 1); x = 127; y = x - (-127); assert(y == -2); return y; } } // ---- // Warning 3944: (116-123): CHC: Underflow (resulting value less than -128) happens here. // Warning 3944: (163-170): CHC: Underflow (resulting value less than -128) happens here. // Warning 4984: (207-217): CHC: Overflow (resulting value larger than 127) happens here.