pragma experimental SMTChecker;

contract C
{
	function f(uint x) public payable {
		assert(blockhash(x) > 0);
		assert(blockhash(2) > 0);
		uint y = x;
		assert(blockhash(x) == blockhash(y));
	}
}
// ----
// Warning 6328: (85-109): CHC: Assertion violation happens here.\nCounterexample:\n\nx = 38\n\nTransaction trace:\nC.constructor()\nC.f(38){ value: 7719 }
// Warning 6328: (113-137): CHC: Assertion violation happens here.\nCounterexample:\n\nx = 38\n\nTransaction trace:\nC.constructor()\nC.f(38){ value: 21238 }