Operational and axiomatic semantics of pcf (original) (raw)
Related papers
1993
We add extensional equalities for the functional and product types to the typed λ-calculus with not only products and terminal object, but also sums and bounded recursion (a version of recursion that does not allow recursive calls of infinite length). We provide a confluent and strongly normalizing (thus decidable) rewriting system for the calculus, that stays confluent when allowing unbounded recursion. For that, we turn the extensional equalities into expansion rules, and not into contractions as is done traditionally. We first prove the calculus to be weakly confluent, which is a more complex and interesting task than for the usual λ-calculus. Then we provide an effective mechanism to simulate expansions without expansion rules, so that the strong normalization of the calculus can be derived from that of the underlying, traditional, non extensional system. These results give us the confluence of the full calculus, but we also show how to deduce confluence without the weak confluence property, using only our technique of simulating expansions.
Combining algebraic rewriting, extensional lambda calculi, and fixpoints
1996
It is well known that confluence and strong normalization are preserved when combining algebraic rewriting systems with the simply typed lambda calculus. It is equally well known that confluence fails when adding either the usual contraction rule for η, or recursion together with the usual contraction rule for surjective pairing.
The lazy lambda calculus with constants
1994
Abstract: In this paper we define the Lazy Lambda Calculus with constants, which extends Abramsky's pure lazy Lambda Calculus. This calculus forms a model for modern lazy functional programming languages. Such languages usually provide a call-by-value facility which is able to distinguish between the values _| _ and\ x. _| _. We study the operational and denotational semantics of this calculus both with and without a superimposed type inference system.
Rewriting with Extensional Polymorphic λ-calculus
2013
We provide a confluent and strongly normalizing rewriting system, based on expansion rules, for the extensional second order typed lambda calculus with product and unit types: this system corresponds to the Intuitionistic Positive Calculus with implication, conjunction, quantification over proposition and the constant True. This result is an important step towards a new theory of reduction based on expansion rules, and gives a natural interpretation to the notion of second order η-long normal forms used in higher order resolution and unification, that are here just the normal forms of our reduction system.