Constraint handling rules with binders, patterns and generic quantification

Abstract

Constraint Handling Rules provide descriptions for constraint solvers. However, they fall short when those constraints specify some binding structure, like higher-rank types in a constraintbased type inference algorithm. In this paper, the term syntax of constraints is replaced by λ-tree syntax, in which binding is explicit; and a new ∇ generic quantifier is introduced, which is used to create new fresh constants. This paper is under consideration for publication in TPLP. * This work was supported by the Netherlands Organisation for Scientific Research (NWO) project on "DOMain Specific Type Error Diagnosis (DOMSTED)" (612.001.213). 1 Since CHRs are Turing-complete (Sneyers et al. 2009), in theory any algorithm can be described. This does not mean that the description is convenient, though.