def reason(store, reasoner="rdfs++"):
    """
    Create a session spec that adds reasoning support to another session.

    :param store: Base session spec.
    :type store: string
    :param reasoner: Reasoning type (e.g. `"rdfs++"`or `"restriction"`).
    :type reasoner: string
    :return: A session spec string.
    :rtype: string
    """
    return "%s[%s]" % (store, reasoner)