15. The textual entailment recognition method according to claim 14 , wherein, in the step (c), in addition to the feature amount, a structural feature of the predicate-argument structure is used to determine whether the first text entails the second text.
15. The textual entailment recognition method according to claim 14 , wherein, in the step (c), in addition to the feature amount, a structural feature of the predicate-argument structure is used to determine whether the first text entails the second text. 16. The textual entailment recognition method according to claim 15 , wherein, in the step (c), determination is performed with preference to one of the feature amount and the structural feature of the predicate-argument structure, in accordance with a structural similarity between the predicate-argument structure of the first text and the predicate-argument structure of the second text.