pragma experimental SMTChecker; abstract contract D { function d() external virtual; } contract C { int x; D d; function set(int n) public { require(n < 100); x = n; } function f() public { x = 0; try d.d() { assert(x < 100); // should hold } catch { assert(x == 0); // should hold, all changes to x has been reverted assert(x == 1); // should fail } } } // ---- // Warning 6328: (348-362): CHC: Assertion violation happens here.\nCounterexample:\nx = 0, d = 0\n\nTransaction trace:\nC.constructor()\nState: x = 0, d = 0\nC.f()