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. // Info 1391: CHC: 3 verification condition(s) proved safe! Enable the model checker option "show proved safe" to see all of them.