contract D {
	constructor(uint _x) { x = _x; }
	function setD(uint _x) public { x = _x; }
	uint public x;
}

contract C {
	uint x;

	function f() public {
		x = 666;
		address d = address(new D(42));
		assert(D(d).x() == 42); // should hold
		assert(D(d).x() == 21); // should fail
		d.call(abi.encodeCall(D.setD, (21)));
		assert(D(d).x() == 21); // should hold, but false positive cus low level calls are not handled precisely
		assert(D(d).x() == 42); // should fail
		assert(x == 666); // should hold, C's storage should not have been havoced
	}
}
// ====
// SMTEngine: chc
// SMTExtCalls: trusted
// SMTIgnoreCex: yes
// ----
// Warning 9302: (284-320): Return value of low-level calls not used.
// Warning 6328: (243-265): CHC: Assertion violation happens here.
// Warning 6328: (324-346): CHC: Assertion violation happens here.
// Warning 6328: (431-453): CHC: Assertion violation happens here.
// Info 1391: CHC: 2 verification condition(s) proved safe! Enable the model checker option "show proved safe" to see all of them.