Function operator-

src/cryptlib/integer.cpp:1755–1776

}

Integer operator-(const Integer &a, const Integer& b)
{
    Integer diff((word)0, STDMAX(a.reg.size, b.reg.size));
    if (a.NotNegative())
    {
        if (b.NotNegative())
            PositiveSubtract(diff, a, b);
        else
            PositiveAdd(diff, a, b);
    }
    else
    {
        if (b.NotNegative())
        {
            PositiveAdd(diff, a, b);
            diff.sign = Integer::NEGATIVE;
        }
        else
            PositiveSubtract(diff, b, a);
    }
    return diff;
}

Integer& Integer::operator-=(const Integer& t)
{