SafeMath.sol

pragma solidity ^0.4.11;

// ----------------------------------------------------------------------------
// OAX 'openANX Token' crowdfunding contract
//
// Refer to http://openanx.org/ for further information.
//
// Enjoy. (c) openANX and BokkyPooBah / Bok Consulting Pty Ltd 2017. 
// The MIT Licence.
// ----------------------------------------------------------------------------


// ----------------------------------------------------------------------------
// Safe maths, borrowed from OpenZeppelin
// ----------------------------------------------------------------------------
library SafeMath {

    // ------------------------------------------------------------------------
    // Add a number to another number, checking for overflows
    // ------------------------------------------------------------------------
    function add(uint a, uint b) internal returns (uint) {
        uint c = a + b;
        assert(c >= a && c >= b);
        return c;
    }

    // ------------------------------------------------------------------------
    // Subtract a number from another number, checking for underflows
    // ------------------------------------------------------------------------
    function sub(uint a, uint b) internal returns (uint) {
        assert(b <= a);
        return a - b;
    }
}