contract C { function f() public pure { uint v = 1; v &= 1; assert(v == 1); v = 7; v &= 3; assert(v != 3); // fails, as 7 & 3 = 3 uint c = 0; c &= v; assert(c == 0); uint8 x = 0xff; uint16 y = 0xffff; y &= x; assert(y == 0xff); assert(y == 0xffff); // fails y = 0xffff; x = 0xff; y &= y | x; assert(y == 0xffff); assert(y == 0xff); // fails } } // ==== // SMTEngine: all // ---- // Warning 6328: (144-158): CHC: Assertion violation happens here. // Warning 6328: (347-366): CHC: Assertion violation happens here. // Warning 6328: (473-490): CHC: Assertion violation happens here. // Info 1391: CHC: 4 verification condition(s) proved safe! Enable the model checker option "show proved safe" to see all of them.