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HasCASL: Towards Integrated Specification and Development of Functional Programs
, 2002
"... The development of programs in modern functional languages such as Haskell calls for a widespectrum specification formalism that supports the type system of such languages, in particular higher order types, type constructors, and parametric polymorphism, and contains a functional language as an exe ..."
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Cited by 25 (11 self)
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The development of programs in modern functional languages such as Haskell calls for a widespectrum specification formalism that supports the type system of such languages, in particular higher order types, type constructors, and parametric polymorphism, and contains a functional language as an executable subset in order to facilitate rapid prototyping. We lay out the design of HasCasl, a higher order extension of the algebraic specification language Casl that is geared towards precisely this purpose. Its semantics is tuned to allow program development by specification refinement, while at the same time staying close to the settheoretic semantics of first order Casl. The number of primitive concepts in the logic has been kept as small as possible; we demonstrate how various extensions to the logic, in particular general recursion, can be formulated within the language itself.
ProofTheoretic Semantics Of ObjectOriented Specification Constructs
, 1990
"... this paper is to show how a collection of specification constructs may be formally defined that supports the former effort. We should stress that we shall not attempt to provide a full and practical specification language that can be used for objectoriented design. We shall have to limit ourselves ..."
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Cited by 17 (5 self)
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this paper is to show how a collection of specification constructs may be formally defined that supports the former effort. We should stress that we shall not attempt to provide a full and practical specification language that can be used for objectoriented design. We shall have to limit ourselves to concentrate on the definition of our main primitive of specification (formalising the notion of object) together with two well known specification constructs: inheritance and aggregation (complex objects). However, we do not see deep problems in extending our results to other useful constructs such as class/type grouping and parameterisation.
An algebraic framework for merging incomplete and inconsistent views
, 2004
"... View merging, also called view integration, is a key problem in conceptual modeling. Large models are often constructed and accessed by manipulating individual views, but it is important to be able to consolidate a set of views to gain a unified perspective, to understand interactions between views, ..."
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Cited by 16 (5 self)
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View merging, also called view integration, is a key problem in conceptual modeling. Large models are often constructed and accessed by manipulating individual views, but it is important to be able to consolidate a set of views to gain a unified perspective, to understand interactions between views, or to perform various types of endtoend analysis. View merging is complicated by incompleteness and inconsistency of views. Once views are merged, it is useful to be able to trace the elements of the merged view back to their sources. In this paper, we propose a framework for merging incomplete and inconsistent graphbased views. We introduce a formalism, called posetannotated graphs, which incorporates a systematic annotation scheme capable of modeling incompleteness and inconsistency as well as providing a builtin mechanism for ownership traceability. We show how structurepreserving maps can capture the relationships between disparate views modeled as posetannotated graphs, and provide a general algorithm for merging views with arbitrary interconnections. We use the i ∗ modeling language [26] as an example to demonstrate how our approach can be applied to existing graphbased modeling languages, especially in the domain of early Requirements Engineering. 1
Algebraic GraphOriented = Category Theory Based  Manifesto of categorizing database theory
, 1996
"... ..."
Combining and Representing Logical Systems Using ModelTheoretic Parchments
 In Recent Trends in Algebraic Development Techniques, volume 1376 of LNCS
, 1997
"... . The paper addresses important problems of building complex logical systems and their representations in universal logics in a systematic way. We adopt the modeltheoretic view of logic as captured in the notions of institution and of parchment (an algebraic way of presenting institutions). We prop ..."
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Cited by 15 (4 self)
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. The paper addresses important problems of building complex logical systems and their representations in universal logics in a systematic way. We adopt the modeltheoretic view of logic as captured in the notions of institution and of parchment (an algebraic way of presenting institutions). We propose a new, modified notion of parchment together with parchment morphisms and representations. In contrast to the original parchment definition and our earlier work, in modeltheoretic parchments introduced here the universal semantic structure is distributed over individual signatures and models. We lift formal properties of the categories of institutions and their representations to this level: the category of modeltheoretic parchments is complete, and their representations may be put together using categorical limits as well. However, modeltheoretic parchments provide a more adequate framework for systematic combination of logical systems than institutions. We indicate how the necessar...
Concepts of ObjectOrientation
 In Proc. of the 2nd Workshop of "Informationssysteme und Kunstliche Intelligenz: Modellierung
, 1992
"... An object is a unit of structure and behavior; it has an identity which persists through change; objects communicate with each other; they are classified by object types, collected into object classes, related by inheritance, and composed to form complex objects. In the first part of the paper, this ..."
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Cited by 13 (10 self)
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An object is a unit of structure and behavior; it has an identity which persists through change; objects communicate with each other; they are classified by object types, collected into object classes, related by inheritance, and composed to form complex objects. In the first part of the paper, this rich world of concepts and constructions is explained in an informal but systematic way, independent of any language or system. In the second part, features of an object specification language are outline which incorporate most of these concepts and constructions. 1 Introduction There are many languages, systems, methods and approaches in computing which call themselves "objectoriented", among them objectoriented programming languages like SmallTalk [GR83], C++ [St86] and Eiffel [Me88], objectoriented database systems like GemStone [BOS91], O 2 [De91], IRIS [Fi87] and ORION [Ki88], and objectoriented system development methods like GOOD [SS86], MOOD [Ke88] and HOOD [Hei88]. Highl...
Combining and Representing Logical Systems
, 1997
"... The paper addresses important problems of building complex logical systems and their representations in universal logics in a systematic way. Following Goguen and Burstall, we adopt the modeltheoretic view of logic as captured in the notion of institution and of parchment (a certain algebraic ..."
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Cited by 12 (3 self)
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The paper addresses important problems of building complex logical systems and their representations in universal logics in a systematic way. Following Goguen and Burstall, we adopt the modeltheoretic view of logic as captured in the notion of institution and of parchment (a certain algebraic way of presenting institutions). We propose a modified notion of parchment together with a notion of parchment morphism and representation, respectively. We lift formal properties of the categories of institutions and their representations to this level: the category of parchments is complete, and parchment representations may be put together using categorical limits as well. However, parchments provide a more adequate framework for systematic combination of logical systems than institutions. We indicate how the necessary invention for proper combination of various logical features may be introduced either on an ad hoc basis (when putting parchments together using limits in the cat...
Algebraic Semantics of Coordination or, what is in a signature?
 Proceedings of the 7th International Conference on Algebraic Methodology and Software Technology (AMAST'98), Amazonia, Brasil, Lecture Notes in Computer Science
, 1999
"... . We propose an algebraic characterisation of the notion of coordination in the sense of recently proposed languages and computational models that provide a clear separation between the modelling of individual software components and their interaction in the overall software organisation. We show ..."
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Cited by 12 (1 self)
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. We propose an algebraic characterisation of the notion of coordination in the sense of recently proposed languages and computational models that provide a clear separation between the modelling of individual software components and their interaction in the overall software organisation. We show how this separation can be captured in Goguen's categorical approach to General Systems Theory and borrow examples from specification logics, program design languages, mathematical models of behaviour, and coordination languages to illustrate the applicability of our algebraic characterisation. 1 Introduction Several recently proposed languages and computational models, e.g. those discussed in [4], support the separation between what, in the definition of a system, is responsible for its computational aspects and what is concerned with coordinating the interaction between its different components. As explained in [12]: "(A) computation model allows programmers to build a single computa...
A Mathematical Toolbox for the Software Architect
, 1996
"... It is suggested that Category Theory provides the right level of mathematical abstraction to address languages for describing software architectures. Contrarily to most other formalisations of SA concepts, Category Theory does not promote any particular formalism for component and connector descript ..."
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Cited by 12 (2 self)
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It is suggested that Category Theory provides the right level of mathematical abstraction to address languages for describing software architectures. Contrarily to most other formalisations of SA concepts, Category Theory does not promote any particular formalism for component and connector description but provides instead the very semantics of the concepts that are related to the gross modularisation of complex systems like "interconnection", "configuration", "instantiation" and "composition". Two examples, a category of programs for a parallel program design language and a category of temporal logic specifications, together with comparisons with other work, namely by Allen and Garlan, and Moriconi and Qian, are adduced to justify this claim. 1. Introduction In a particularly stimulating panel introduction, Garlan and Perry present an overview of current research issues in Software Architecture (SA) [11]. They characterise SA to be "emerging as a significant and different design lev...
A Compositional Approach to Structuring and Refinement of Typed Graph Grammars
 Proc. of SEGRAGRA'95 "Graph Rewriting and Computation", Electronic Notes of TCS
, 1995
"... Based on a categorical semantics that has been developed for typed graph grammars we uses colimits (pushouts) to model composition and (reverse) graph grammar morphisms to describe refinements of typed graph grammars. Composition of graph grammars w.r.t. common subgrammars is shown to be compatible ..."
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Cited by 11 (2 self)
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Based on a categorical semantics that has been developed for typed graph grammars we uses colimits (pushouts) to model composition and (reverse) graph grammar morphisms to describe refinements of typed graph grammars. Composition of graph grammars w.r.t. common subgrammars is shown to be compatible with the semantics, i.e. the semantics of the composed grammar is obtained as the composition of the semantics of the component grammars. Moreover, the structure of a composed grammar is preserved during a refinement step in the sense that compatible refinements of the components induce a refinement of the composition. The concepts and results are illustrated by an example. 1 Introduction This contribution addresses the structuring and refinement of typed graph grammars defined according to the algebraic double pushout approach [5]. Typed graph grammars are introduced in [2] for the double pushout approach (cf. [6] for a corresponding notion in the singlepushout setting). They generalize ...