It is well-known that many environment-based abstract machines can be seen as strategies
in lambda calculi with explicit substitutions (ES). Recently, graphical syntaxes and linear …

The development of programming languages can be quite complicated and costly. Hence,
much effort has been devoted to the modular definition of language features that can be …

Abstract machines for functional languages rely on the notion of environment, a data
structure storing the previously encountered and delayed beta-redexes. This paper provides …

A cornerstone of the theory of λ-calculus is that intersection types characterise termination
properties. They are a flexible tool that can be adapted to various notions of termination, and …

The existing call-by-need λ describe lazy evaluation via equational logics. A programmer
can use these logics to safely ascertain whether one term is behaviorally equivalent to …

This paper studies useful sharing, which is a sophisticated optimization for lambda-calculi, in
the context of call-by-need evaluation in presence of open terms. Useful sharing turns out to …

Functional logic programming and probabilistic programming have demonstrated the broad
benefits of combining laziness (nonstrict evaluation with sharing of the results) with …

We present the first operational account of call by need that connects syntactic theory and
implementation practice. Syntactic theory: the storeless operational semantics using syntax …

We present a generalization of the refocusing procedure that provides a generic method for
deriving an abstract machine from a specification of a reduction semantics satisfying simple …

We study call-by-need from the point of view of the duality between call-by-name and call-by-
value. We develop sequent-calculus style versions of call-by-need both in the minimal and …