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113
Cognitive perspectives of information retrieval interaction: elements of a cognitive IR theory
 Journal of Documentation
, 1996
"... The objective of the paper is to amalgamate theories of text retrieval from various research traditions into a cognitive theory for information retrieval interaction. Set in a cognitive framework, the paper outlines the concept of polyrepresentation applied to both the user's cognitive space and the ..."
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Cited by 116 (8 self)
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The objective of the paper is to amalgamate theories of text retrieval from various research traditions into a cognitive theory for information retrieval interaction. Set in a cognitive framework, the paper outlines the concept of polyrepresentation applied to both the user's cognitive space and the information space of IR systems. The concept seeks to represent the current user's information need, problem state, and domain work task or interest in a structure of causality. Further, it implies that we should apply different methods of representation and a variety of IR techniques of different cognitive and functional origin simultaneously to each semantic fulltext entity in the information space. The cognitive differences imply that by applying cognitive overlaps of information objects, originating from different interpretations of such objects through time and by type, the degree of uncertainty inherent in IR is decreased. Polyrepresentation and the use of cognitive overlaps are associated with, but not identical to, data
Productive Use of Failure in Inductive Proof
 Journal of Automated Reasoning
, 1995
"... Proof by mathematical induction gives rise to various kinds of eureka steps, e.g. missing lemmata, generalization, etc. Most inductive theorem provers rely upon user intervention in supplying the required eureka steps. ..."
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Cited by 97 (22 self)
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Proof by mathematical induction gives rise to various kinds of eureka steps, e.g. missing lemmata, generalization, etc. Most inductive theorem provers rely upon user intervention in supplying the required eureka steps.
Automating the Meta Theory of Deductive Systems
, 2000
"... not be interpreted as representing the o cial policies, either expressed or implied, of NSF or the U.S. Government. This thesis describes the design of a metalogical framework that supports the representation and veri cation of deductive systems, its implementation as an automated theorem prover, a ..."
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Cited by 81 (17 self)
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not be interpreted as representing the o cial policies, either expressed or implied, of NSF or the U.S. Government. This thesis describes the design of a metalogical framework that supports the representation and veri cation of deductive systems, its implementation as an automated theorem prover, and experimental results related to the areas of programming languages, type theory, and logics. Design: The metalogical framework extends the logical framework LF [HHP93] by a metalogic M + 2. This design is novel and unique since it allows higherorder encodings of deductive systems and induction principles to coexist. On the one hand, higherorder representation techniques lead to concise and direct encodings of programming languages and logic calculi. Inductive de nitions on the other hand allow the formalization of properties about deductive systems, such as the proof that an operational semantics preserves types or the proof that a logic is is a proof calculus whose proof terms are recursive functions that may be consistent.M +
A Calculus for and Termination of Rippling
 Journal of Automated Reasoning
, 1996
"... . Rippling is a type of rewriting developed for inductive theorem proving that uses annotations to direct search. Rippling has many desirable properties: for example, it is highly goal directed, usually involves little search, and always terminates. In this paper we give a new and more general forma ..."
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Cited by 41 (2 self)
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. Rippling is a type of rewriting developed for inductive theorem proving that uses annotations to direct search. Rippling has many desirable properties: for example, it is highly goal directed, usually involves little search, and always terminates. In this paper we give a new and more general formalization of rippling. We introduce a simple calculus for rewriting annotated terms, close in spirit to firstorder rewriting, and prove that it has the formal properties desired of rippling. Next we develop criteria for proving the termination of such annotated rewriting, and introduce orders on annotated terms that lead to termination. In addition, we show how to make rippling more flexible by adapting the termination orders to the problem domain. Our work has practical as well as theoretical advantages: it has led to a very simple implementation of rippling that has been integrated in the Edinburgh CLAM system. Key words: Mathematical Induction, Inductive Theorem Proving, Term Rewriting. ...
The PROSPER Toolkit
, 2000
"... The Prosper (Proof and Specification Assisted Design Environments) project advocates the use of toolkits which allow existing verification tools to be adapted to a more flexible format so that they may be treated as components. A system incorporating such tools becomes another component that can be ..."
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Cited by 39 (2 self)
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The Prosper (Proof and Specification Assisted Design Environments) project advocates the use of toolkits which allow existing verification tools to be adapted to a more flexible format so that they may be treated as components. A system incorporating such tools becomes another component that can be embedded in an application. This paper describes the Prosper Toolkit which enables this. The nature of communication between components is specified in a languageindependent way. It is implemented in several common programming languages to allow a wide variety of tools to have access to the toolkit.
Logic Program Synthesis
, 1993
"... This paper presents an overview and a survey of logic program synthesis. Logic program synthesis is interpreted here in a broad way; it is concerned with the following question: given a specification, how do we get a logic program satisfying the specification? Logic programming provides a uniquely n ..."
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Cited by 38 (10 self)
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This paper presents an overview and a survey of logic program synthesis. Logic program synthesis is interpreted here in a broad way; it is concerned with the following question: given a specification, how do we get a logic program satisfying the specification? Logic programming provides a uniquely nice and uniform framework for program synthesis since the specification, the synthesis process and the resulting program can all be expressed in logic. Three main approaches to logic program synthesis by formal methods are described: constructive synthesis, deductive synthesis and inductive synthesis. Related issues such as correctness and verification as well as synthesis by informal methods are briefly presented. Our presentation is made coherent by employing a unified framework of terminology and notation, and by using the same running example for all the approaches covered. This paper thus intends to provide an assessment of existing work and a framework for future research in logic program synthesis.
MiddleOut Reasoning for Logic Program Synthesis
 IN 10TH INTERNATIONAL CONFERENCE ON LOGIC PROGRAMMING (ICLP93
, 1993
"... We propose a novel approach to automating the synthesis of logic programs: Logic programs are synthesized as a byproduct of the planning of a verification proof. The approach is a twolevel one: At the object level, we prove program verification conjectures in a sorted, firstorder theory. The c ..."
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Cited by 31 (8 self)
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We propose a novel approach to automating the synthesis of logic programs: Logic programs are synthesized as a byproduct of the planning of a verification proof. The approach is a twolevel one: At the object level, we prove program verification conjectures in a sorted, firstorder theory. The conjectures are of the form 8args \Gamma\Gamma\Gamma\Gamma! : prog(args \Gamma\Gamma\Gamma\Gamma! ) $ spec(args \Gamma\Gamma\Gamma\Gamma! ). At the metalevel, we plan the objectlevel verification with an unspecified program definition. The definition is represented with a (secondorder) metalevel variable, which becomes instantiated in the course of the planning.
Termination analysis for functional programs using term orderings
 IN PROCEEDINGS OF THE SECOND INTERNATIONAL STATIC ANALYSIS SYMPOSIUM, LNCS 983
, 1995
"... To prove the termination of a functional program there has to be a wellfounded ordering such that the arguments in each recursive call are smaller than the corresponding inputs. In this paper we present a procedure for automated termination proofs of functional programs. In contrast to previously p ..."
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Cited by 31 (12 self)
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To prove the termination of a functional program there has to be a wellfounded ordering such that the arguments in each recursive call are smaller than the corresponding inputs. In this paper we present a procedure for automated termination proofs of functional programs. In contrast to previously presented methods a suited wellfounded ordering does not have to be fixed in advance by the user, but can be synthesized automatically. For that purpose we use approaches developed in the area of term rewriting systems for the automated generation of suited wellfounded term orderings. But unfortunately term orderings cannot be directly used for termination proofs of functional programs which call other algorithms in the arguments of their recursive calls. The reason is that while for the termination of term rewriting systems orderings between terms are needed, for functional programs we need orderings between objects of algebraic data types. Our method solves this problem and enables term orderings to be used for termination proofs of functional programs.
PDS  A ThreeDimensional Data Structure for Proof Plans
 PROC. OF ACIDCA'2000
, 2000
"... We present a new data structure that enables to store threedimensional proof objects in a proof development environment. The aim is to handle calculus level proofs as well as abstract proof plans together with information of their correspondences in a single structure. This enables not only differe ..."
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Cited by 28 (8 self)
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We present a new data structure that enables to store threedimensional proof objects in a proof development environment. The aim is to handle calculus level proofs as well as abstract proof plans together with information of their correspondences in a single structure. This enables not only different means of the proof development environment (e.g., rule and tacticbased theorem proving, or proof planning) to act directly on the same proof object but it also allows for easy presentation of proofs on different levels of abstraction. However, the threedimensional structure requires adjustment of the regular techniques for addition and deletion of proof lines and backtracking of the proof planner.