import re


def has_arg(unknown_args, short_form, long_form):
    """
    check whether a conceptual arg is present in a list of command line tokens

    :param unknown_args: list of command line tokens
    :param short_form: dash followed by single letter, e.g. '-f'
    :param long_form: double dash followed by work, e.g. '--forks'
    :return: boolean
    """

    assert re.match(r'^-[a-zA-Z0-9]$', short_form)
    assert re.match(r'^--\w+$', long_form)
    if long_form in unknown_args:
        return True
    for arg in unknown_args:
        if arg.startswith(short_form):
            return True
    return False