Natural Language Deduction with Incomplete Information
Natural Language Deduction with Incomplete Information
复制标题
DOI:
10.48550/arxiv.2211.00614
复制
发表时间:
2022-11
期刊:
影响因子:
--
通讯作者:
Zayne Sprague;Kaj Bostrom;Swarat Chaudhuri;Greg Durrett
中科院分区:
文献类型:
--
作者:
Zayne Sprague;Kaj Bostrom;Swarat Chaudhuri;Greg Durrett
A growing body of work studies how to answer a question or verify a claim by generating a natural language “proof:” a chain of deductive inferences yielding the answer based on a set of premises. However, these methods can only make sound deductions when they follow from evidence that is given. We propose a new system that can handle the underspecified setting where not all premises are stated at the outset; that is, additional assumptions need to be materialized to prove a claim. By using a natural language generation model to abductively infer a premise given another premise and a conclusion, we can impute missing pieces of evidence needed for the conclusion to be true. Our system searches over two fringes in a bidirectional fashion, interleaving deductive (forward-chaining) and abductive (backward-chaining) generation steps. We sample multiple possible outputs for each step to achieve coverage of the search space, at the same time ensuring correctness by filtering low-quality generations with a round-trip validation procedure. Results on a modified version of the EntailmentBank dataset and a new dataset called Everyday Norms: Why Not? Show that abductive generation with validation can recover premises across in- and out-of-domain settings.