Learning definite Horn formulas from closure queries

详细信息    查看全文

• 作者：Marta Arias^a ; ¹ ; ³ ; ^{marias@cs.upc.edu} ; José ; L. Balcá ; zar^a ; ¹ ; ³ ; ^{jose.luis.balcazar@upc.edu} ; Cristina Tî ; rnăucă^b ; ¹ ; ² ; ^{cristina.tirnauca@unican.es}
• 关键词：Query learning ; Definite Horn clauses ; Closure operators
• 刊名：Theoretical Computer Science
• 出版年：2017
• 出版时间：7 January 2017
• 年：2017
• 卷：658
• 期：part_PB
• 页码：346-356
• 全文大小：387 K
• 卷排序：658

文摘

A definite Horn theory is a set of n-dimensional Boolean vectors whose characteristic function is expressible as a definite Horn formula, that is, as conjunction of definite Horn clauses. The class of definite Horn theories is known to be learnable under different query learning settings, such as learning from membership and equivalence queries or learning from entailment. We propose yet a different type of query: the closure query. Closure queries are a natural extension of membership queries and also a variant, appropriate in the context of definite Horn formulas, of the so-called correction queries. We present an algorithm that learns conjunctions of definite Horn clauses in polynomial time, using closure and equivalence queries, and show how it relates to the canonical Guigues–Duquenne basis for implicational systems. We also show how the different query models mentioned relate to each other by either showing full-fledged reductions by means of query simulation (where possible), or by showing their connections in the context of particular algorithms that use them for learning definite Horn formulas.