Extending Liquid Types to Arrays



Downloads per month over past year

Montenegro Montes, Manuel and Nieva Soto, Susana and Peña Marí, Ricardo and Segura Díaz, Clara María (2020) Extending Liquid Types to Arrays. ACM Transactions on Computational Logic, 21 (2). pp. 1-41. ISSN 1529-3785

[thumbnail of main.pdf]

Official URL: https://dl.acm.org/doi/10.1145/3362740


A liquid type is an ordinary Hindley-Milner type annotated with a logical predicate that states the properties satisfied by the elements of that type. Liquid types are a powerful tool for program verification, since programmers can use them to specify pre- and postconditions of their programs, while the predicates of intermediate variables and auxiliary functions are inferred automatically. Type inference is feasible in this context, since the logical predicates within liquid types are constrained to a quantifier-free logic in order to maintain decidability.

In this paper we extend liquid types by allowing them to contain quantified properties on arrays, so that they can be used to infer invariants on array-related programs (for example, implementations of sorting algorithms). Although quantified logic is, in general, undecidable, we restrict properties on arrays to a decidable subset introduced by Bradley et al. We describe in detail the extended type system, the verification condition generator, and the iterative weakening algorithm for inferring invariants. After proving the correctness and completeness of these two algorithms, we apply them to find invariants on a set of algorithms involving array manipulations.

Item Type:Article
Uncontrolled Keywords:Dependent Types, Liquid Types, Invariant Synthesis
Palabras clave (otros idiomas):Tipos dependientes, Tipos Liquid, Síntesis de Invariantes
Subjects:Sciences > Computer science > Programming languages (Electronic computers)
Sciences > Computer science > Computer programming
Sciences > Computer science > Software
Sciences > Mathematics > Logic, Symbolic and mathematical
ID Code:71766
Deposited On:19 Apr 2022 07:31
Last Modified:19 Apr 2022 07:31

Origin of downloads

Repository Staff Only: item control page