Dignāga’s Logic –problems of interpretation

In the article an example of logic and epistemology of the Buddhist philosopher Dignaga indicates some limitations of both standard logic languages and adequacy of basic epistemological concepts: meaning and truth. Contrary to the methodological lines suggested by Łukasiewicz and Schayer, the structure of inference schema anumāna is not determined by truth-functional operator between sentences. Semantic inference structure is determined by generic name, relation qualifications on the basis of distributive or collective class. The Buddhist inference can not be reflected by the relationship between a cause and an effect. The recognition of the thesis is the result of applying the operation to the exclusion (apoha) of other meanings for the hetu premise. At the level of syntax, the cognitive act of agreement with the thesis of inference (based on the exclusion of other meanings for the hetu) is expressed with the ablative case (separation) by the suffix “-at”.In the article an example of logic and epistemology of the Buddhist philosopher Dignaga indicates some limitations of both standard logic languages and adequacy of basic epistemological concepts: meaning and truth. Contrary to the methodological lines suggested by Łukasiewicz and Schayer, the structure of inference schema anumāna is not determined by truth-functional operator between sentences. Semantic inference structure is determined by generic name, relation qualifications on the basis of distributive or collective class. The Buddhist inference can not be reflected by the relationship between a cause and an effect. The recognition of the thesis is the result of applying the operation to the exclusion (apoha) of other meanings for the hetu premise. At the level of syntax, the cognitive act of agreement with the thesis of inference (based on the exclusion of other meanings for the hetu) is expressed with the ablative case (separation) by the suffix “-at”

Unifying Class-Based Representation Formalisms

The notion of class is ubiquitous in computer science and is central in many formalisms for the representation of structured knowledge used both in knowledge representation and in databases. In this paper we study the basic issues underlying such representation formalisms and single out both their common characteristics and their distinguishing features. Such investigation leads us to propose a unifying framework in which we are able to capture the fundamental aspects of several representation languages used in different contexts. The proposed formalism is expressed in the style of description logics, which have been introduced in knowledge representation as a means to provide a semantically well-founded basis for the structural aspects of knowledge representation systems. The description logic considered in this paper is a subset of first order logic with nice computational characteristics. It is quite expressive and features a novel combination of constructs that has not been studied before. The distinguishing constructs are number restrictions, which generalize existence and functional dependencies, inverse roles, which allow one to refer to the inverse of a relationship, and possibly cyclic assertions, which are necessary for capturing real world domains. We are able to show that it is precisely such combination of constructs that makes our logic powerful enough to model the essential set of features for defining class structures that are common to frame systems, object-oriented database languages, and semantic data models. As a consequence of the established correspondences, several significant extensions of each of the above formalisms become available. The high expressiveness of the logic we propose and the need for capturing the reasoning in different contexts forces us to distinguish between unrestricted and finite model reasoning. A notable feature of our proposal is that reasoning in both cases is decidable. We argue that, by virtue of the high expressive power and of the associated reasoning capabilities on both unrestricted and finite models, our logic provides a common core for class-based representation formalisms

Compiling ER Specifications into Declarative Programs

This paper proposes an environment to support high-level database programming in a declarative programming language. In order to ensure safe database updates, all access and update operations related to the database are generated from high-level descriptions in the entity- relationship (ER) model. We propose a representation of ER diagrams in the declarative language Curry so that they can be constructed by various tools and then translated into this representation. Furthermore, we have implemented a compiler from this representation into a Curry program that provides access and update operations based on a high-level API for database programming.Comment: Paper presented at the 17th Workshop on Logic-based Methods in Programming Environments (WLPE2007

A Survey of Languages for Specifying Dynamics: A Knowledge Engineering Perspective

A number of formal specification languages for knowledge-based systems has been developed. Characteristics for knowledge-based systems are a complex knowledge base and an inference engine which uses this knowledge to solve a given problem. Specification languages for knowledge-based systems have to cover both aspects. They have to provide the means to specify a complex and large amount of knowledge and they have to provide the means to specify the dynamic reasoning behavior of a knowledge-based system. We focus on the second aspect. For this purpose, we survey existing approaches for specifying dynamic behavior in related areas of research. In fact, we have taken approaches for the specification of information systems (Language for Conceptual Modeling and TROLL), approaches for the specification of database updates and logic programming (Transaction Logic and Dynamic Database Logic) and the generic specification framework of abstract state machine

Genuine Process Logic

The Genuine Process Logic described here (abbreviation: GPL) places the object-bound process itself at the center of formalism. It should be suitable for everyday use, i.e. it is not primarily intended for the formalization of computer programs, but instead, as a counter-conception to the classical state logics. The new and central operator of the GPL is an action symbol replacing the classical state symbols, e.g. of equivalence or identity. The complete renunciation of object-language state expressions also results in a completely new metalinguistic framework, both regarding the axioms and the expressive possibilities of this system. A mixture with state logical terms is readily possible