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Polymorphic Type Inference and Abstract Data Types
 ACM Transactions on Programming Languages and Systems
, 1994
"... Data Types Konstantin Läufer Martin Odersky Loyola University of Chicago Universität Karlsruhe laufer@math.luc.edu odersky@ira.uka.de June 5, 1994 Technical Report LUC001 Abridged version appeared in Transactions of Programming Languages and Systems Abstract Many staticallytyped programming lan ..."
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Cited by 61 (3 self)
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Data Types Konstantin Läufer Martin Odersky Loyola University of Chicago Universität Karlsruhe laufer@math.luc.edu odersky@ira.uka.de June 5, 1994 Technical Report LUC001 Abridged version appeared in Transactions of Programming Languages and Systems Abstract Many staticallytyped programming languages provide an abstract data type construct, such as the module in Modula2. However, in most of these languages, implementations of abstract data types are not firstclass values. Thus they cannot be assigned to variables, passed as function parameters, or returned as function results. Several higherorder functional languages feature strong and static type systems, parametric polymorphism, algebraic data types, and explicit type variables. Most of them rely on Hindley Milner type inference instead of requiring explicit type declarations for identifiers. Although some of these languages support abstract data types, it appears that none of them directly provides lightweight abstract dat...
A characterization of partial metrizability: Domains are quantifiable
 Theoretical Computer Science
, 2001
"... A characterization of partial metrizability is given which provides a partial solution to an open problem stated by Kunzi in the survey paper Nonsymmetric Topology ([Kun93], problem 7 ). The characterization yields a powerful tool which establishes a correspondence between partial metrics and ..."
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Cited by 7 (3 self)
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A characterization of partial metrizability is given which provides a partial solution to an open problem stated by Kunzi in the survey paper Nonsymmetric Topology ([Kun93], problem 7 ). The characterization yields a powerful tool which establishes a correspondence between partial metrics and special types of valuations, referred to as Qvaluations (cf. also [Sch00]). The notion of a Qvaluation essentially combines the wellknown notion of a valuation with a weaker version of the notion of a quasiunimorphism, i.e. an isomorphism in the context of quasiuniform spaces. As an application, we show that #continuous dcpo's are quantifiable in the sense of [O'N97], i.e. the Scott topology and partial order are induced by a partial metric. For #algebraic dcpo's the Lawson topology is induced by the associated metric. The partial metrization of general domains improves prior approaches in two ways:  The partial metric is guaranteed to capture the Scott topology as opposed to e.g. [Smy87],[BvBR95],[FS96] and [FK97], which in general yield a coarser topology.
Formalising a Model of the lambdacalculus in HOLST
, 1994
"... Most new theorem provers implement strong and complicated type theories which eliminate some of the limitations of simple type theories such as the HOL logic. A more accessible alternative might be to use a combination of set theory and simple type theory as in HOLST which is a version of the HOL s ..."
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Cited by 3 (0 self)
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Most new theorem provers implement strong and complicated type theories which eliminate some of the limitations of simple type theories such as the HOL logic. A more accessible alternative might be to use a combination of set theory and simple type theory as in HOLST which is a version of the HOL system supporting a ZFlike set theory in addition to higher order logic. This paper presents a case study on the use of HOLST to build a model of the calculus by formalising the inverse limit construction of domain theory. This construction is not possible in the HOL system itself, or in simple type theories in general. 1 Introduction The HOL system [GM93] supports a simple and accessible yet very powerful logic, called higher order logic or simple type theory. This is probably a main reason why it has one of the largest user communities of any theorem prover today. However, it is heard every now and then that users cannot quite do what they would like to do, e.g. due to restrictions in t...
ContextFree Event Domains are recognizable
, 1995
"... The possibly non distributive event domains which arise from Winskel's event structures with binary conflict are known to coincide with the domains of configurations of Stark's trace automata. We prove that whenever the transitive reduction of the order on finite elements in an event domain is a con ..."
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The possibly non distributive event domains which arise from Winskel's event structures with binary conflict are known to coincide with the domains of configurations of Stark's trace automata. We prove that whenever the transitive reduction of the order on finite elements in an event domain is a contextfree graph in the sense of Muller and Schupp, that event domain may also be generated from a finite trace automaton, where both the set of states and the concurrent alphabet are finite. We show that the set of graph grammars which generate event domains is a recursive set. We obtain altogether an effective procedure which decides from an unlabelled graph grammar whether it generates an event domain and which constructs in that case a finite trace automaton recognizing that event domain. The advantage of trace automata over unlabelled graph grammars is to provide for a more concrete and therefore more tractable representation of event domains, well suited to an automated verification o...