How can I link a library with public function?

[magj2006]

Hey, If I have a lib: Math.sol and a normal contract: Number.sol.

library Math {

/**
 * @dev Returns the largest of two numbers.
 */
function max(uint256 a, uint256 b) public pure returns (uint256) {
    return a > b ? a : b;
}

/**
 * @dev Returns the smallest of two numbers.
 */
function min(uint256 a, uint256 b) public pure returns (uint256) {
    return a < b ? a : b;
}

}

contract Counter {
using Math for uint256;
uint256 public maxNumber;
function setMaxNumber(uint256 a, uint256 b) external {
maxNumber = a.max(b);
}
}

how can I import Math lib？ if I directly define them in same project, I can't build them due to an error: LLVM IR generator definition pass error.
I tried to separate define them in two project, and I builded and deployed Math. then how can I import it ? I already published Math
to npmjs, and imported it from npm path, and using --libraries to build, still failed.