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SetTheoretical and Other Elementary Models of the lambdacalculus
 Theoretical Computer Science
, 1993
"... Part 1 of this paper is the previously unpublished 1972 memorandum [43], with editorial changes and some minor corrections. Part 2 presents what happened next, together with some further development of the material. The first part begins with an elementary settheoretical model of the ficalculus. F ..."
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Cited by 40 (0 self)
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Part 1 of this paper is the previously unpublished 1972 memorandum [43], with editorial changes and some minor corrections. Part 2 presents what happened next, together with some further development of the material. The first part begins with an elementary settheoretical model of the ficalculus. Functions are modeled in a similar way to that normally employed in set theory, by their graphs; difficulties are caused in this enterprise by the axiom of foundation. Next, based on that model, a model of the fijcalculus is constructed by means of a natural deduction method. Finally, a theorem is proved giving some general properties of those nontrivial models of the fijcalculus which are continuous complete lattices. The second part begins with a brief discussion of models of the calculus in set theories with antifoundation axioms. Next the model of the fi calculus of Part 1 and also the closely relatedbut different!models of Scott [53, 54] and of Engeler [21, 22] are reviewed....
A settheoretical definition of application
 University of Edinburgh
, 1972
"... [41], with editorial changes and some minor corrections. Part 2 presents what happened next, together with some further development of the material. The first part begins with an elementary settheoretical model of the λβcalculus. Functions are modelled in a similar way to that normally employed in ..."
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Cited by 7 (0 self)
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[41], with editorial changes and some minor corrections. Part 2 presents what happened next, together with some further development of the material. The first part begins with an elementary settheoretical model of the λβcalculus. Functions are modelled in a similar way to that normally employed in set theory, by their graphs; difficulties are caused in this enterprise by the axiom of foundation. Next, based on that model, a model of the λβηcalculus is constructed by means of a natural deduction method. Finally, a theorem is proved giving some general properties of those nontrivial models of the λβηcalculus which are continuous complete lattices. In the second part we begin with a brief discussion of models of the λcalculus in set theories with antifoundation axioms. Next we review the model of the λβcalculus of Part 1 and also the closely related—but different!—models of Scott [51, 52] and of Engeler [19, 20]. Then we discuss general frameworks in which elementary constructions of models can be given. Following Longo [36], one can employ certain ScottEngeler algebras.
A Filter Model for Concurrent λCalculus
 SIAM J. Comput
, 1998
"... Type free lazy calculus is enriched with angelic parallelism and demonic nondeterminism. Callbyname and callbyvalue abstractions are considered and the operational semantics is stated in terms of a must convergence predicate. We introduce a type assignment system with intersection and union typ ..."
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Cited by 4 (1 self)
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Type free lazy calculus is enriched with angelic parallelism and demonic nondeterminism. Callbyname and callbyvalue abstractions are considered and the operational semantics is stated in terms of a must convergence predicate. We introduce a type assignment system with intersection and union types and we prove that the induced logical semantics is fully abstract.
A Convex Powerdomain over Lattices: its Logic and λCalculus
, 1997
"... . To model at the same time parallel and nondeterministic functional calculi we define a powerdomain functor P such that it is an endofunctor over the category of algebraic lattices. P is locally continuous and we study the initial solution D 1 of the domain equation D = P([D ! D]? ). We derive f ..."
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Cited by 1 (1 self)
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. To model at the same time parallel and nondeterministic functional calculi we define a powerdomain functor P such that it is an endofunctor over the category of algebraic lattices. P is locally continuous and we study the initial solution D 1 of the domain equation D = P([D ! D]? ). We derive from the algebras of P the logic of D 1 , that is the axiomatic description of its compact elements. We then define a calculus and a type assignment system using the logic of D 1 as the related type theory. We prove that the filter model of this calculus, which is isomorphic to D 1 , is fully abstract with respect to the observational preorder of the calculus. Keywords: calculus, Nondeterminism, Full Abstraction, Powerdomain Construction, Intersection Type Disciplines. 1. Introduction One of the main issues in the design of programming languages is the achievement of a good compromise between the multiplicity of control structures and data types and the unicity of the mathematica...
Intersection Types, λmodels, and Böhm Trees
"... This paper is an introduction to intersection type disciplines, with the aim of illustrating their theoretical relevance in the foundations of λcalculus. We start by describing the wellknown results showing the deep connection between intersection type systems and normalization properties, i.e. ..."
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This paper is an introduction to intersection type disciplines, with the aim of illustrating their theoretical relevance in the foundations of λcalculus. We start by describing the wellknown results showing the deep connection between intersection type systems and normalization properties, i.e., their power of naturally characterizing solvable, normalizing, and strongly normalizing pure λterms. We then explain the importance of intersection types for the semantics of λcalculus, through the construction of filter models and the representation of algebraic lattices. We end with an original result that shows how intersection types also allow to naturally characterize tree representations of unfoldings of λterms (Böhm trees).
Behavioural Inverse Limit λModels
, 2003
"... We construct two inverse limit λmodels which completely characterise sets of terms with similar computational behaviours: the sets of normalising, head normalising, weak head normalising λterms, those corresponding to the persistent versions of these notions, and the sets of closable, closable nor ..."
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We construct two inverse limit λmodels which completely characterise sets of terms with similar computational behaviours: the sets of normalising, head normalising, weak head normalising λterms, those corresponding to the persistent versions of these notions, and the sets of closable, closable normalising, and closable head normalising λterms. More precisely, for each of these sets of terms there is a corresponding element in at least one of the two models such that a term belongs to the set if and only if its interpretation (in a suitable environment) is greater than or equal to that element. We use the finitary logical description of the models, obtained by defining suitable intersection type assignment systems, to prove this.