<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def combine_relevance_tables(relevance_tables):
 """ Create a combined relevance table out of a list of relevance tables, aggregating the p-values and the relevances. :param relevance_tables: A list of relevance tables :type relevance_tables: List[pd.DataFrame] :return: The combined relevance table :rtype: pandas.DataFrame """

    def _combine(a, b):
        a.relevant |= b.relevant
        a.p_value = a.p_value.combine(b.p_value, min, 1)
        return a

    return reduce(_combine, relevance_tables)