Finitary Corecursion for the Infinitary Lambda Calculus
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چکیده
Kurz et al. have recently shown that infinite λ-trees with finitely many free variables modulo α-equivalence form a final coalgebra for a functor on the category of nominal sets. Here we investigate the rational fixpoint of that functor. We prove that it is formed by all rational λtrees, i.e. those λ-trees which have only finitely many subtrees (up to isomorphism). This yields a corecursion principle that allows the definition of operations such as substitution on rational λ-trees. 1998 ACM Subject Classification F.3.2 Semantics of Programming Languages, F.4.1 Mathematical Logic, D.3.1 Formal Definitions and Theory
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تاریخ انتشار 2015