- Email: [email protected]
IV in Lisp
360
Abstracts
R. Maiocchi and B. Pernici: Time Reasoning in the Office Environment, Dipartimento di Elettronica, Politecnico di Miiano, Oct. 1985. In the office environment temporal aspects are important to mark documents and to coordinate activities. The TSOS time model for office information systems provides the capability of specifying time aspects. Temporal specifications are organized in classes; then, with the time expert, it is possible to answer questions about temporal specification. The answers about time evolution of the office system are precise to the maximum possible extent. When only possible to give an approximate answer, this is done with the maximum level of precision that can be achieved. The proposed method for dealing with time specifications and the time expert for reasoning on time are general and can be applied not only to Office Information Systems, but also to Information Systems and Database Systems. Author's Abstract
William C. Mann and Sandra A. Thompson: Rhetorical Structure Theory: Description and Construction of text Structures, Information Sciences Institute, Marina del Rey, October 1986. Rhetorical Structure Theory (RST) is a theory of text structure that is being extended to serve as a theoretical basis for computational text planning. Text structure in RST are hierarchic, builts on small patterns called schemas. The schemas which compose the structural hierarchy of a text describe the functions of the parts rather than their form characteristics. Relations between text parts, comparable to conjunctive relations, are a prominent part of RST's definitional machinery. Recent work on RST has put it onto a new definitional basis. This paper describes the current status of descriptive RST, along with efforts to create a constructive version for use as a basis for programming a text planner. Authors' Abstract
William C. Mann and Sandra A. Thompson: Rhetorical Structure Theory: A Framework for the Analysis of Texts, Information Sciences Institute, Marina del Rey, 1987. Rhetorical Structure Theory is a theory of text organization which provides a framework for an analysis of text. The theory is based on the understanding that a test is not merely a string of clauses, but consists instead of hierarchically organized gro,,aps of clauses that stand in various relations to one another. There 'rhetorical relations' can be described functionally in terms of the purposes of the writer and the writer's assumptions about *,he reader. They hold between two adjacent parts of a text, where, typically, one part is 'nuclear' and one a 'satellite'. An analysis of a text consists in identifying the relations holding between successively larger parts of the text, yielding a natural hierarclfical description of the rhetorical organization of the text. The paper informally outlines RST's mechanisms and applications, which include studies of clause combining, coherence and assertional effects of discourse structure. RST characteristically provides comprehensive analyses rather than selective commentary. RST is insensitive to text size, and has been applied to a wide variety of sizes of text. Author's Abstract
Alexander Ollongren: On the Implementation of parts of Meta/IV in Lisp, Software Systems Research Center, Linkoeping Institute of Technology, April 1981. Meta-IV, the meta-language of the Vienna Development Method, has been designed as a supporting language for the formal definition of high-level programming languages and information processing systems. Its basic features are the use of abstract grammars to delimit universes of discourse and the use of (primitive) recursive functions. In the present paper we show that parts of Meta-lV can be implemented in LISP. In order to do so we first decide to use the set of so-called generalised multilevel arrays and two fundamental operations on them (selection and assignment) as the basic datatype. This implies at once that not full Meta-lv is considered but only that part of it
Abstracts
361
for which the set of arrays and operations form a homomorphic image. Next the implementation of the basic datatype in LISP is explained; the implementation s carried out in such a way that the basic datatype forms a homomorphic image of the LISP datastructure chosen (association lists) under the operations of selection and assignment. In this way we obtain starting from Meta-IV, a LISP implementation via two steps of datatype refinement. An example of an information processing systems formalized in Meta-IV is given and the transformation to an executable LISP program is carried out. In the same manner an incremental compiler for the skeleton of an ALGOL-like programming language is developed.
B. Pernici and W. Vogel: An Integrated Approach to OIS Development, Esprit Technical Week '86, Bruxelles, Sept. 1986.
Author's Abstract
Yoav Raz: Supporting Natural Language Interfaces for Relational Databases Using RRA - A Reshaped Relational Algebra, Department of Computer Science, Technion - Israel Institute of Technology, Haifa, May 1986.
Ewa Orlowska: Logic for reasoning about Knowledge, Institute of Computer Science, Polish Academy of Sciences, Warsaw, October 1986. Semantics for knowledge operators is introduced based on the rough set theory. An epistemic logic is defined and its expressive power is discussed. Several paradoxes of epistemic logics are shown to be diminated in the given system. Authors' Abstract
Oesten Oskarsson and Henrik Soerensen: Integrating Documentation and Program Code, Software Systems research Center, Linkoeping University, December 1980. This paper discusses the use of powerful programming environments to improve the maintainability of program documentation. It ~s claimed that this can be done by keeping prc~gram and documentation in a database with acces:~ to facilities for administration and document production. An example from an existing prcgramming environment is given. Author s Abstract
The goal of Project 'Automatic tools for designing office systems' (TODOS) within the Office Systems area of ESPRIT is that of making Office Information Systems development easier, quicker, and more reliable by providing a set of design tools to analysts, designers, and users. Techniques for collecting design data, rapid prototyping, and choosing system architecture are studied in the project. This paper presents the project, started in January 1986, and its first results. Author's Abstract
A methodology based on RRA for constructing portable Natural Lang:uage (NL) interface for relational databases is presented. This methodology differs from other approaches in assuming that for database NL queries, a 'rough' analysis is sufficient in most cases to extract the intended meaning, and hence, bypassing many difficult problems of NL processing. RRA - the Reshaped Relational Algebra is equivalent to the regular Relational Algebra (RA), but has different operators. Its operators, a modification of the RA's operators, are intended to follow the semantics of queries phrased in Natural English Language (NL). For each operator there are appropriate elementary syntactical constructs of natural language. These elementary constructs can be combined for form complex sentences (queries), whose semantics is given by algebraic expressions composed of corresponding operators. The above set of syntactical constructs provides the elements for the 'rough' analysis of NL queries and proves itself as rich enough to express most queries that 'make sense'. As such, the RRA is useful both in defining semantics for Natural Language subsets of languages alike, and in implementing efficiently NL translators for interfaces to relational databases. Another important idea behind the presented
Abstracts
R. Maiocchi and B. Pernici: Time Reasoning in the Office Environment, Dipartimento di Elettronica, Politecnico di Miiano, Oct. 1985. In the office environment temporal aspects are important to mark documents and to coordinate activities. The TSOS time model for office information systems provides the capability of specifying time aspects. Temporal specifications are organized in classes; then, with the time expert, it is possible to answer questions about temporal specification. The answers about time evolution of the office system are precise to the maximum possible extent. When only possible to give an approximate answer, this is done with the maximum level of precision that can be achieved. The proposed method for dealing with time specifications and the time expert for reasoning on time are general and can be applied not only to Office Information Systems, but also to Information Systems and Database Systems. Author's Abstract
William C. Mann and Sandra A. Thompson: Rhetorical Structure Theory: Description and Construction of text Structures, Information Sciences Institute, Marina del Rey, October 1986. Rhetorical Structure Theory (RST) is a theory of text structure that is being extended to serve as a theoretical basis for computational text planning. Text structure in RST are hierarchic, builts on small patterns called schemas. The schemas which compose the structural hierarchy of a text describe the functions of the parts rather than their form characteristics. Relations between text parts, comparable to conjunctive relations, are a prominent part of RST's definitional machinery. Recent work on RST has put it onto a new definitional basis. This paper describes the current status of descriptive RST, along with efforts to create a constructive version for use as a basis for programming a text planner. Authors' Abstract
William C. Mann and Sandra A. Thompson: Rhetorical Structure Theory: A Framework for the Analysis of Texts, Information Sciences Institute, Marina del Rey, 1987. Rhetorical Structure Theory is a theory of text organization which provides a framework for an analysis of text. The theory is based on the understanding that a test is not merely a string of clauses, but consists instead of hierarchically organized gro,,aps of clauses that stand in various relations to one another. There 'rhetorical relations' can be described functionally in terms of the purposes of the writer and the writer's assumptions about *,he reader. They hold between two adjacent parts of a text, where, typically, one part is 'nuclear' and one a 'satellite'. An analysis of a text consists in identifying the relations holding between successively larger parts of the text, yielding a natural hierarclfical description of the rhetorical organization of the text. The paper informally outlines RST's mechanisms and applications, which include studies of clause combining, coherence and assertional effects of discourse structure. RST characteristically provides comprehensive analyses rather than selective commentary. RST is insensitive to text size, and has been applied to a wide variety of sizes of text. Author's Abstract
Alexander Ollongren: On the Implementation of parts of Meta/IV in Lisp, Software Systems Research Center, Linkoeping Institute of Technology, April 1981. Meta-IV, the meta-language of the Vienna Development Method, has been designed as a supporting language for the formal definition of high-level programming languages and information processing systems. Its basic features are the use of abstract grammars to delimit universes of discourse and the use of (primitive) recursive functions. In the present paper we show that parts of Meta-lV can be implemented in LISP. In order to do so we first decide to use the set of so-called generalised multilevel arrays and two fundamental operations on them (selection and assignment) as the basic datatype. This implies at once that not full Meta-lv is considered but only that part of it
Abstracts
361
for which the set of arrays and operations form a homomorphic image. Next the implementation of the basic datatype in LISP is explained; the implementation s carried out in such a way that the basic datatype forms a homomorphic image of the LISP datastructure chosen (association lists) under the operations of selection and assignment. In this way we obtain starting from Meta-IV, a LISP implementation via two steps of datatype refinement. An example of an information processing systems formalized in Meta-IV is given and the transformation to an executable LISP program is carried out. In the same manner an incremental compiler for the skeleton of an ALGOL-like programming language is developed.
B. Pernici and W. Vogel: An Integrated Approach to OIS Development, Esprit Technical Week '86, Bruxelles, Sept. 1986.
Author's Abstract
Yoav Raz: Supporting Natural Language Interfaces for Relational Databases Using RRA - A Reshaped Relational Algebra, Department of Computer Science, Technion - Israel Institute of Technology, Haifa, May 1986.
Ewa Orlowska: Logic for reasoning about Knowledge, Institute of Computer Science, Polish Academy of Sciences, Warsaw, October 1986. Semantics for knowledge operators is introduced based on the rough set theory. An epistemic logic is defined and its expressive power is discussed. Several paradoxes of epistemic logics are shown to be diminated in the given system. Authors' Abstract
Oesten Oskarsson and Henrik Soerensen: Integrating Documentation and Program Code, Software Systems research Center, Linkoeping University, December 1980. This paper discusses the use of powerful programming environments to improve the maintainability of program documentation. It ~s claimed that this can be done by keeping prc~gram and documentation in a database with acces:~ to facilities for administration and document production. An example from an existing prcgramming environment is given. Author s Abstract
The goal of Project 'Automatic tools for designing office systems' (TODOS) within the Office Systems area of ESPRIT is that of making Office Information Systems development easier, quicker, and more reliable by providing a set of design tools to analysts, designers, and users. Techniques for collecting design data, rapid prototyping, and choosing system architecture are studied in the project. This paper presents the project, started in January 1986, and its first results. Author's Abstract
A methodology based on RRA for constructing portable Natural Lang:uage (NL) interface for relational databases is presented. This methodology differs from other approaches in assuming that for database NL queries, a 'rough' analysis is sufficient in most cases to extract the intended meaning, and hence, bypassing many difficult problems of NL processing. RRA - the Reshaped Relational Algebra is equivalent to the regular Relational Algebra (RA), but has different operators. Its operators, a modification of the RA's operators, are intended to follow the semantics of queries phrased in Natural English Language (NL). For each operator there are appropriate elementary syntactical constructs of natural language. These elementary constructs can be combined for form complex sentences (queries), whose semantics is given by algebraic expressions composed of corresponding operators. The above set of syntactical constructs provides the elements for the 'rough' analysis of NL queries and proves itself as rich enough to express most queries that 'make sense'. As such, the RRA is useful both in defining semantics for Natural Language subsets of languages alike, and in implementing efficiently NL translators for interfaces to relational databases. Another important idea behind the presented