Results 1  10
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409
Is the Harrison, Ruzzo, Ullman Undecidable Proof Flawed?
, 2001
"... This paper is a followup report to a reading assignment and questionable flaw of the HRU Model and proof of its reachability. A special instance of a Turing machine is considered by a challenge made to the correctness of the original proof. The inspection of this challenge concludes with the disco ..."
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This paper is a followup report to a reading assignment and questionable flaw of the HRU Model and proof of its reachability. A special instance of a Turing machine is considered by a challenge made to the correctness of the original proof. The inspection of this challenge concludes
A New Method for Undecidability Proofs of First Order Theories
 Journal of Symbolic Computation
, 1992
"... this paper is to define a framework for such reduction proofs. The method proposed is illustrated by proving the undecidability of the theory of a term algebra modulo the axioms of associativity and commutativity and of the theory of a partial lexicographic path ordering. 1. Introduction ..."
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Cited by 30 (6 self)
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this paper is to define a framework for such reduction proofs. The method proposed is illustrated by proving the undecidability of the theory of a term algebra modulo the axioms of associativity and commutativity and of the theory of a partial lexicographic path ordering. 1. Introduction
Undecidability of Plane Polygonal Mereotopology
 PRINCIPLES OF KNOWLEDGE REPRESENTATION AND REASONING: PROCEEDINGS OF THE 6TH INTERNATIONAL CONFERENCE (KR98
, 1998
"... This paper presents a mereotopological model of polygonal regions of the Euclidean plane and an undecidability proof of its firstorder theory. Restricted to the primitive operations the model is a Boolean algebra. Its single primitive predicate defines simple polygons as the topologically simplest p ..."
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Cited by 22 (0 self)
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This paper presents a mereotopological model of polygonal regions of the Euclidean plane and an undecidability proof of its firstorder theory. Restricted to the primitive operations the model is a Boolean algebra. Its single primitive predicate defines simple polygons as the topologically simplest
Bounded Quantification is Undecidable
 Information and Computation
, 1993
"... F is a typed calculus with subtyping and bounded secondorder polymorphism. First proposed by Cardelli and Wegner, it has been widely studied as a core calculus for type systems with subtyping. Curien and Ghelli proved the partial correctness of a recursive procedure for computing minimal types of ..."
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Cited by 108 (9 self)
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of F terms and showed that the termination of this procedure is equivalent to the termination of its major component, a procedure for checking the subtype relation between F types. This procedure was thought to terminate on all inputs, but the discovery of a subtle bug in a purported proof
PVS: Combining Specification, Proof Checking, and Model Checking
, 1996
"... rem Proving and Typechecking The PVS specification language is based on classical, simply typed higherorder logic, but the type system has been augmented with subtypes and dependent types. Though typechecking is undecidable for the PVS type system, the PVS typechecker automatically checks for simp ..."
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Cited by 230 (5 self)
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rem Proving and Typechecking The PVS specification language is based on classical, simply typed higherorder logic, but the type system has been augmented with subtypes and dependent types. Though typechecking is undecidable for the PVS type system, the PVS typechecker automatically checks
Diagonalisation proof of the undecidability of the Halting Problem
, 2006
"... Here are some brief notes on the classic proof of the undecidability of the Halting Problem. The lecture notes don’t explictly cover the technique of diagonalisation, but it’s an important ..."
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Here are some brief notes on the classic proof of the undecidability of the Halting Problem. The lecture notes don’t explictly cover the technique of diagonalisation, but it’s an important
Communication Errors in the πCalculus are Undecidable
"... We present an undecidability proof of the notion of communication errors in the polyadic #calculus. The demonstration follows a general pattern of undecidability proofs  reducing a wellknown undecidable problem to the problem in question. We make use of an encoding of the #calculus into the ..."
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Cited by 1 (0 self)
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We present an undecidability proof of the notion of communication errors in the polyadic #calculus. The demonstration follows a general pattern of undecidability proofs  reducing a wellknown undecidable problem to the problem in question. We make use of an encoding of the #calculus
The Undecidability of kProvability
 Annals of Pure and Applied Logic
, 1989
"... The kprovability problem is, given a first order formula φ and an integer k, to determine if φ has a proof consisting of k or fewer lines (i.e., formulas or sequents). This paper shows that the kprovability problem for the sequent calculus is undecidable. Indeed, for every r.e. srt ..."
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Cited by 34 (0 self)
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The kprovability problem is, given a first order formula φ and an integer k, to determine if φ has a proof consisting of k or fewer lines (i.e., formulas or sequents). This paper shows that the kprovability problem for the sequent calculus is undecidable. Indeed, for every r
Undecidability of the unification and admissibility problems for modal and description logics
, 2006
"... We show that the unification problem ‘is there a substitution instance of a given formula that is provable in a given logic?’ is undecidable for basic modal logics K and K4 extended with the universal modality. It follows that the admissibility problem for inference rules is undecidable for these lo ..."
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Cited by 17 (0 self)
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of the universal modality), thereby showing that these problems are undecidable for basic hybrid logics. Recently, unification has been introduced as an important reasoning service for description logics. The undecidability proof for K with nominals can be used to show the undecidability of unification for Boolean
Termination Of Graph Rewriting Is Undecidable
, 1998
"... It is shown that it is undecidable in general whether a graph rewriting system (in the "double pushout approach") is terminating. The proof is by a reduction of the Post Correspondence Problem. It is also argued that there is no straightforward reduction of the halting problem for Turin ..."
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Cited by 23 (2 self)
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It is shown that it is undecidable in general whether a graph rewriting system (in the "double pushout approach") is terminating. The proof is by a reduction of the Post Correspondence Problem. It is also argued that there is no straightforward reduction of the halting problem
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