Unification of Deterministic Higher-Order Patterns
Open Access
- 24 July 2026
- book chapter
- Published by Springer Nature
- p. 200-216
Abstract
We present a sound and complete unification procedure for deterministic higher-order patterns, a class of simply-typed lambda terms introduced by Yokoyama et al. which comes with a deterministic matching problem. Our unification procedure can be seen as a special case of full higher-order unification where flex-flex pairs can be solved in a most general way. Moreover, our method generalizes Libal and Miller’s recent functions-as-constructors higher-order unification (FCU) by dropping their global restriction on variable arguments, thereby losing the property that every solvable problem has a most general unifier. In fact, minimal complete sets of unifiers of deterministic higher-order patterns may be infinite, so decidability of the unification problem remains an open question.Keywords
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This publication has 19 references indexed in Scilit:
- Superposition for Higher-Order LogicJournal of Automated Reasoning, 2023
- Functions-as-constructors higher-order unification: extended pattern unificationAnnals of Mathematics and Artificial Intelligence, 2021
- Extensional Higher-Order Paramodulation in Leo-IIIJournal of Automated Reasoning, 2021
- Deterministic second-order patternsInformation Processing Letters, 2004
- Deterministic Higher-Order Patterns for Program TransformationLecture Notes in Computer Science, 2004
- Isabelle/HOL2002
- Higher-Order Unification and Matching2001
- TPS: A theorem-proving system for classical type theoryJournal of Automated Reasoning, 1996
- Linear unification of higher-order patterns1993
- A unification algorithm for typed λ-calculusTheoretical Computer Science, 1975