// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity =0.6.12;

import '../libraries/BitMath.sol';

contract BitMathEchidnaTest {
    function mostSignificantBitInvariant(uint256 input) external pure {
        uint8 msb = BitMath.mostSignificantBit(input);
        assert(input >= (uint256(2)**msb));
        assert(msb == 255 || input < uint256(2)**(msb + 1));
    }

    function leastSignificantBitInvariant(uint256 input) external pure {
        uint8 lsb = BitMath.leastSignificantBit(input);
        assert(input & (uint256(2)**lsb) != 0);
        assert(input & (uint256(2)**lsb - 1) == 0);
    }
}