J. F. Costa, A. Sernadas & C. Sernadas, Object Inheritance Beyond Subtyping, Acta Informatica 31, pp. 5-26, Springer-Verlag, 1994.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....of reasoning about the database schema on a high level of abstraction. However, it is built on the view based data modeling which does not fit the context of the model proposed in the standard ODMG 93. Similar direction leading to an interesting abstraction of inheritance can be found in [3] and [7] Their approach is more suitable for our purpose. We can summarize, that this work focuses on the structural character of objectoriented paradigm but does not consider the dynamic aspects. It also does not deal with the other properties such as the data encapsulation, static and dynamic ....

....to as the axioms of the specification. The theory presented by ( Theta; Phi) consists just of the set of formulas which are consequences of Phi (its theorems) Presentations are not closed under the consequence and, therefore, are generally finite and can be used for specification. Similarly in [3], the authors use the same categorical framework in which theory presentations are substituted by the process models. The inheritance is modeled by using the limit construction in the same manner in both works. It illustrates the strong unifying property of CT enabling to find interesting ....

[Article contains additional citation context not shown here]

COSTA, J., SERNADAS, A., SERNADAS, C.: Object Inheritance Beyond Subtyping. Acta Informatica, 1994.

....object oriented programming languages. Therefore, a major research direction is to extend the constraint language of deductive systems so that it can fit into the object oriented paradigm. Concurrency in object based systems has been investigated in the extended process algebra framework [35, 55]. By contrast, concurrency in logical systems is based on a theoretical approach developed specifically for this type of systems [56] In general, most concurrent logical languages consider concurrency among processes expressed as atoms in queries. The variables, shared among atoms, are ....

F. Costa, A. Sernadas, and C. Sernadas. Object Inheritance Beyond Subtyping. Acta Lnfor- matira, 31:5 26, 1994. Springer-Verlag, Berlin.

....all behaviors over Delta satisfying Phi. Bspec seq has final elements. A final element is obtained as the subbehavior of a final element in Delta seq determined by all life cycles satisfying Phi. Consequently, final elements in Bspec seq are definite. The finality results are contained in [CSS94] We may utilize these results for assigning standard semantics to temporal template specifications in an abstract way, i.e. up to isomorphism. However, we cannot specify nondefinite behavior this way. In order to increase specification power and manageability, we envisage to give direct ....

J.F. Costa, A. Sernadas, and C. Sernadas. Object Inheritance Beyond Subtyping. Acta Informatica 31 (1994), 5-26

....of an object behavior specification into a constraint programming language, and some proofs are shown. 2 Object Model Objects are communicating entities represented by a couple #BEHAV IOR CONTROL, STRUCTURE#. This kind of presentation has been used by the ESPRIT BRA Working Group IS CORE [CSS94] in order to give a semantic based on categories for inheritance in the case of sequential objects. The group proposes the following model for an object, ##Events, ##, #Att, # e,a e#Events,a#Att ## where Events is the set of incoming events such as methods call, # the accepted ....

....of parallel behavior within the object, and the representation of expected parallel behavior. So the behavior control system specifies dynamic aspects of the object: causal dependency between methods, accepted sequences of events, temporal constraints. 4. 3 Contexts Slot alphabet [CSS94, pages 11, 12] Given a finite family of sets V AL, a slot alphabet is a pair Att = #V AR,Cod# where V AR is a finite set (of names of attributes) and Cod is a map from V AR into V AL. 2 For each variable v # V AR, Cod returns its codomain. Cod(a) is the set of possible values the attribute ....

J.F. Costa, A. Sernedas, and C. Sernedas. Object inheritance beyond subtyping. Acta Informatica, 31:5--26, 1994.

....and interaction, specialization and generalization, aggregation and synchronization [296, 295] 245] presents a semantic domain for processes with initiative and discusses the relevance for object semantics. 246] presents a categorial semantics for process communication. Subsequent papers ( [243, 244]) present further results concerning inheritance even in the presence of overriding. 350] proposes a canonical semantics of temporal object specifications. 294] studies dynamic specialization, i.e. object roles and phases. An institution for a simple logic of behaviour using a cofibration from ....

J. Costa, A. Sernadas, and C. Sernadas. Object Inheritance Beyond Subtyping. Acta Informatica, 31:5--26, 1995. \Phi.

....the popularity of category theory in some fields of computing science, not many applications in the field of information systems can be found in the literature. Recently, however, it seems that this is changing. Categorical formalizations of (aspects of) object orientation (see e.g. ES91, FSMS91, CSS94] object oriented data models (see e.g. Sie90, Tui94] ER (see e.g. DJM92] and the Relational Model (see e.g. IP94, BSW94] have been proposed. In [SFMS89] a categorical framework for the axiomatization of conceptual modeling concepts is described (based on the notion of institution) In ....

J.F. Costa, A. Sernadas, and C. Sernadas. Object inheritance beyond subtyping. Acta Informatica, 31(1):5--26, January 1994.

....the popularity of category theory in some fields of computing science, not many applications in the field of information systems can be found in the literature. Recently, however, it seems that this is changing. Categorical formalizations of (aspects of) object orientation (see e.g. ES91, FSMS91, CSS94] object oriented data models (see e.g. Sie90, Tui94] ER (see e.g. DJM92] and the Relational Model (see e.g. IP94, BSW94] have been proposed. In [SFMS89] a categorical framework for the axiomatization of conceptual modeling concepts is described (based on the notion of institution) In ....

J.F. Costa, A. Sernadas, and C. Sernadas. Object inheritance beyond subtyping. Acta Informatica, 31(1):5--26, January 1994.

....the popularity of category theory in some fields of computing science, not many applications in the field of information systems can be found in the literature. Recently, however, it seems that this is changing. Categorical formalizations of (aspects of) object orientation (see e.g. ES91, FSMS91, CSS94] object oriented data models (see e.g. Sie90, Tui94] ER (see e.g. DJM92] and the Relational Model (see e.g. IP94, BSW94] have been proposed. In [SFMS89] a categorical framework for the axiomatization of conceptual modeling concepts is described (based on the notion of institution) In ....

J.F. Costa, A. Sernadas, and C. Sernadas. Object inheritance beyond subtyping. Acta Informatica, 31(1):5--26, January 1994.

....the popularity of category theory in some fields of computing science, not many applications in the field of information systems can be found in the literature. Recently, however, it seems that this is changing. Categorical formalizations of (aspects of) object orientation (see e.g. ES91, FSMS91, CSS94] object oriented data models (see e.g. Sie90, Tui94] ER (see e.g. DJM92] and the Relational Model (see e.g. IP94, BSW94] have been proposed. In [SFMS89] a categorical framework for the axiomatization of conceptual modeling concepts is described (based on the notion of institution) In ....

J.F. Costa, A. Sernadas, and C. Sernadas. Object inheritance beyond subtyping. Acta Informatica, 31(1):5--26, January 1994.

....of reasoning about the database schema on a high level of abstraction. However, it is built on the view based data modeling which does not fit the context of the model proposed in the standard ODMG 93. Similar direction leading to an interesting abstraction of inheritance can be found in [3] and [7] Their approach is more suitable for our purpose. We can summarize, that this work focuses on the structural character of objectoriented paradigm but does not consider the dynamic aspects. It also does not deal with the other properties such as the data encapsulation, static and dynamic ....

....to as the axioms of the specification. The theory presented by ( Theta; Phi) consists just of the set of formulas which are consequences of Phi (its theorems) Presentations are not closed under the consequence and, therefore, are generally finite and can be used for specification. Similarly in [3], the authors use the same categorical framework in which theory presentations are substituted by the process models. The inheritance is modeled by using the limit construction in the same manner in both works. It illustrates the strong unifying property of CT enabling to find interesting ....

[Article contains additional citation context not shown here]

COSTA, J., SERNADAS, A., SERNADAS, C.: Object Inheritance Beyond Subtyping. Acta Informatica, 1994.

....#) be a specification. Let Cspec class be the full subcategory of # class consisting of all classes over # satisfying #. Cspec class has final elements. A final element is obtained as the maximal subclass of a final element in # class satisfying #. Correcponding finality results are given in [CSS94] We may utilize these results for assigning standard abstract semantics to temporal class specifications. In order to increase specification power and manageability, we envisage to give direct axiomatic specification only to basic classes. Derived and complex classes may be specified using ....

J.F. Costa, A. Sernadas, and C. Sernadas. Object Inheritance Beyond Subtyping. Acta Informatica 31 (1994), 5-26.

....in the form of classes, objects, data structures and the like, and their relationships. Many existing conceptual models and systems view these two constructs as distinct. My claim is that they are not: relationships are a specialization of entities. Relationships come in several forms, inheritance[12], connectors[20, 43] and aggregation[7] being the most common. All of these constructs can be described and utilized as first class entities. They can be formally modeled, specialized, applied to other constructs, and refined. Individual relationships also have relationships to each other, thus ....

J.F. Costa, A. Sernadas, and C. Sernadas. Object inheritance beyond subtyping. Acta Informatica, 31(1):5--26, 1994.

No context found.

J. F. Costa, A. Sernadas & C. Sernadas, Object Inheritance Beyond Subtyping, Acta Informatica 31, pp. 5-26, Springer-Verlag, 1994.

No context found.

Costa, J.F., A. Sernadas and C. Sernadas, Object inheritancebeyond subtyping, Acta Informatica 31, pp. 5-26, Springer-Verlag, 1994.

....Also, we only establish soundness. It should be possible to obtain a (relative) completeness result but that is a topic for further research. The proposed logic is monotonic, although we recognize that a full account of object specialization (with overriding) will need non monotonic features [BL91, CSS94]. We assume that the reader is conversant with the field of temporal logic specification (for instance at the level of [McA76, Gol87] For an overview see [Eme90] We also use a little bit of category theory (the reader may find all relevant concepts in the introductory chapters of any textbook ....

....specialization (and aggregation) may only add new theorems. We are aware that such a monotonic approach may not be sufficient. For instance, specialization with overriding is non monotonic. This question should be addressed in subsequent work, maybe along the lines proposed for semantic domains in [CSS94] using the notion of partial morphism. However, it does not seem trivial to lift such a notion to the level of theories. Work in this direction is already presented in [BLR93] based upon an earlier version of the logic presented herein. Another limitation of the proposed logic is the impossibility ....

J. Costa, A. Sernadas, and C. Sernadas. Object inheritance beyond subtyping. Acta Informatica, 31:5--26, 1994.

No context found.

J.F.Costa, A.Sernadas and C.Sernadas, "Object Inheritance Beyond Subtyping", INESC Report, 1992, to appear in Acta Informatica

No context found.

J. F. Costa, A. Sernadas and C. Sernadas, "Object inheritance beyond subtyping ", Acta Informatica 31 (1992) pp. 5--26.

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC