contract C { uint x; bool once; constructor() payable { x = address(this).balance; } function f() public payable { require(!once); once = true; require(msg.value > 0); assert(address(this).balance > x); // should hold assert(address(this).balance > x + 10); // should fail } } // ==== // SMTEngine: all // ---- // Warning 4984: (266-272): CHC: Overflow (resulting value larger than 2**256 - 1) happens here.\nCounterexample:\nx = 115792089237316195423570985008687907853269984665640564039457584007913129639926, once = true\n\nTransaction trace:\nC.constructor(){ msg.value: 28100 }\nState: x = 115792089237316195423570985008687907853269984665640564039457584007913129639926, once = false\nC.f(){ msg.value: 8 } // Warning 6328: (235-273): CHC: Assertion violation happens here.\nCounterexample:\nx = 0, once = true\n\nTransaction trace:\nC.constructor(){ msg.value: 0 }\nState: x = 0, once = false\nC.f(){ msg.value: 8 } // Info 1180: Contract invariant(s) for :C:\nonce\n