pragma experimental SMTChecker; // 2 warnings, fallback and A.g contract A { uint x; fallback () external virtual { assert(x == 1); } function g() public view { assert(x == 1); } } // 2 warnings, fallback and A.g contract B is A { uint y; fallback () external override { assert(x == 1); } } // ---- // Warning 6328: (122-136): CHC: Assertion violation happens here.\nCounterexample:\nx = 0\n\n\n\nTransaction trace:\nA.constructor()\nState: x = 0\nA.fallback() // Warning 6328: (171-185): CHC: Assertion violation happens here.\nCounterexample:\nx = 0\n\n\n\nTransaction trace:\nA.constructor()\nState: x = 0\nA.g() // Warning 6328: (288-302): CHC: Assertion violation happens here.\nCounterexample:\ny = 0, x = 0\n\n\n\nTransaction trace:\nB.constructor()\nState: y = 0, x = 0\nB.fallback()