contract A { int public x; function f() public virtual { x = 1; } } contract B is A { function f() public virtual override { super.f(); x += 100; } } contract C is B { function f() public virtual override { super.f(); x += 10; } } contract D is B { } contract E is C,D { function f() public override(C,B) { super.f(); assert(x == 111); // should hold assert(x == 13); // should fail } } // ==== // SMTEngine: all // ---- // Warning 6328: (379-394): CHC: Assertion violation happens here.\nCounterexample:\nx = 111\n\nTransaction trace:\nE.constructor()\nState: x = 0\nE.f()\n C.f() -- internal call\n B.f() -- internal call\n A.f() -- internal call // Info 1180: Contract invariant(s) for :C:\n((x = 0) || (x = 111))\nContract invariant(s) for :D:\n((x = 0) || (x = 101))\nContract invariant(s) for :E:\n((x = 0) || (x = 111))\nContract invariant(s) for :B:\n((x = 0) || (x = 101))\n