Order-Sorted Equality Enrichments Modulo Axioms

Built-in equality and inequality predicates based on comparison of canonical forms in algebraic specifications are frequently used because they are handy and efficient. However, their use places algebraic specifications with initial algebra semantics beyond the pale of theorem proving tools based, f...

Full description

Autores:
Gutiérrez, Raúl
Meseguer, José
Rocha, Camilo
Tipo de recurso:
Part of book
Fecha de publicación:
2012
Institución:
Escuela Colombiana de Ingeniería Julio Garavito
Repositorio:
Repositorio Institucional ECI
Idioma:
eng
OAI Identifier:
oai:repositorio.escuelaing.edu.co:001/1859
Acceso en línea:
https://repositorio.escuelaing.edu.co/handle/001/1859
Palabra clave:
Teoría Ecuacional
Obligación de prueba
Transformación de la teoría
Especificación algebraica
Álgebra Inicial
Equational Theory
Proof Obligation
Theory Transformation
Algebraic Specification
Initial Algebra
Rights
closedAccess
License
http://purl.org/coar/access_right/c_14cb
id ESCUELAIG2_9a7ffa1ac003bc18d6edfa8dd529c4ef
oai_identifier_str oai:repositorio.escuelaing.edu.co:001/1859
network_acronym_str ESCUELAIG2
network_name_str Repositorio Institucional ECI
repository_id_str
dc.title.eng.fl_str_mv Order-Sorted Equality Enrichments Modulo Axioms
title Order-Sorted Equality Enrichments Modulo Axioms
spellingShingle Order-Sorted Equality Enrichments Modulo Axioms
Teoría Ecuacional
Obligación de prueba
Transformación de la teoría
Especificación algebraica
Álgebra Inicial
Equational Theory
Proof Obligation
Theory Transformation
Algebraic Specification
Initial Algebra
title_short Order-Sorted Equality Enrichments Modulo Axioms
title_full Order-Sorted Equality Enrichments Modulo Axioms
title_fullStr Order-Sorted Equality Enrichments Modulo Axioms
title_full_unstemmed Order-Sorted Equality Enrichments Modulo Axioms
title_sort Order-Sorted Equality Enrichments Modulo Axioms
dc.creator.fl_str_mv Gutiérrez, Raúl
Meseguer, José
Rocha, Camilo
dc.contributor.author.none.fl_str_mv Gutiérrez, Raúl
Meseguer, José
Rocha, Camilo
dc.contributor.researchgroup.spa.fl_str_mv Informática
dc.subject.armarc.spa.fl_str_mv Teoría Ecuacional
Obligación de prueba
Transformación de la teoría
Especificación algebraica
Álgebra Inicial
topic Teoría Ecuacional
Obligación de prueba
Transformación de la teoría
Especificación algebraica
Álgebra Inicial
Equational Theory
Proof Obligation
Theory Transformation
Algebraic Specification
Initial Algebra
dc.subject.proposal.eng.fl_str_mv Equational Theory
Proof Obligation
Theory Transformation
Algebraic Specification
Initial Algebra
description Built-in equality and inequality predicates based on comparison of canonical forms in algebraic specifications are frequently used because they are handy and efficient. However, their use places algebraic specifications with initial algebra semantics beyond the pale of theorem proving tools based, for example, on explicit or inductionless induction techniques, and of other formal tools for checking key properties such as confluence, termination, and sufficient completeness. Such specifications would instead be amenable to formal analysis if an equationally-defined equality predicate enriching the algebraic data types were to be added to them. Furthermore, having an equationally-defined equality predicate is very useful in its own right, particularly in inductive theorem proving. Is it possible to effectively define a theory transformation E↦E≃ that extends an algebraic specification E to a specification E≃ having an equationally-defined equality predicate? This paper answers this question in the affirmative for a broad class of order-sorted conditional specifications E that are sort-decreasing, ground confluent, and operationally terminating modulo axioms B and have a subsignature of constructors. The axioms B can consist of associativity, or commutativity, or associativity-commutativity axioms, so that the constructors are free modulo B. We prove that the transformation E↦E≃ preserves all the just-mentioned properties of E . The transformation has been automated in Maude using reflection and is used in several Maude formal tools.
publishDate 2012
dc.date.issued.none.fl_str_mv 2012
dc.date.accessioned.none.fl_str_mv 2021-11-27T16:01:46Z
dc.date.available.none.fl_str_mv 2021-11-27T16:01:46Z
dc.type.spa.fl_str_mv Capítulo - Parte de Libro
dc.type.coar.fl_str_mv http://purl.org/coar/resource_type/c_2df8fbb1
dc.type.coarversion.fl_str_mv http://purl.org/coar/version/c_970fb48d4fbd8a85
dc.type.version.spa.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.coar.spa.fl_str_mv http://purl.org/coar/resource_type/c_3248
dc.type.content.spa.fl_str_mv Text
dc.type.driver.spa.fl_str_mv info:eu-repo/semantics/bookPart
dc.type.redcol.spa.fl_str_mv http://purl.org/redcol/resource_type/ART
format http://purl.org/coar/resource_type/c_3248
status_str publishedVersion
dc.identifier.isbn.none.fl_str_mv 9783642340055
dc.identifier.uri.none.fl_str_mv https://repositorio.escuelaing.edu.co/handle/001/1859
identifier_str_mv 9783642340055
url https://repositorio.escuelaing.edu.co/handle/001/1859
dc.language.iso.spa.fl_str_mv eng
language eng
dc.relation.ispartofseries.none.fl_str_mv Lecture Notes in Computer Science book series (LNCS);7571
dc.relation.indexed.spa.fl_str_mv N/A
dc.relation.ispartofbook.eng.fl_str_mv Rewriting Logic and Its Applications
dc.relation.references.spa.fl_str_mv Baader, F., Nipkow, T.: Term Rewriting and All That. Cambridge University Press (1998)
Bergstra, J., Tucker, J.: Characterization of Computable Data Types by Means of a Finite Equational Specification Method. In: de Bakker, J.W., van Leeuwen, J. (eds.) ICALP 1980. LNCS, vol. 81, pp. 76–90. Springer, Heidelberg (1980)
Clavel, M., Durán, F., Eker, S., Lincoln, P., Martí-Oliet, N., Meseguer, J., Talcott, C.: All About Maude - A High-Performance Logical Framework. LNCS, vol. 4350. Springer, Heidelberg (2007)
Durán, F., Lucas, S., Marché, C., Meseguer, J., Urbain, X.: Proving Operational Termination of Membership Equational Programs. Higher Order Symbolic Computation 21(1-2), 59–88 (2008)
Durán, F., Lucas, S., Meseguer, J.: Termination Modulo Combinations of Equational Theories. In: Ghilardi, S., Sebastiani, R. (eds.) FroCoS 2009. LNCS, vol. 5749, pp. 246–262. Springer, Heidelberg (2009)
Durán, F., Meseguer, J.: On the Church-Rosser and Coherence Properties of Conditional Order-Sorted Rewrite Theories. Journal of Logic and Algebraic Programming (2011) (to appear)
Goguen, J., Meseguer, J.: Order-Sorted Algebra I: Equational Deduction for Multiple Inheritance, Overloading, Exceptions and Partial Operations. Theoretical Computer Science 105, 217–273 (1992)
Goguen, J.A.: How to Prove Algebraic Inductive Hypotheses Without Induction. In: Bibel, W., Kowalski, R. (eds.) CADE 1980. LNCS, vol. 87, pp. 356–373. Springer, Heidelberg (1980)
Gutiérrez, R., Meseguer, J., Rocha, C.: Order-Sorted Equality Enrichments Modulo Axioms (Extended Version). Tech. rep., University of Illinois at Urbana-Champaing (December 2011), http://hdl.handle.net/2142/28597
Hendrix, J.: Decision Procedures for Equationally Based Reasoning. Ph.D. thesis, Department of Computer Science, University of Illinois at Urbana-Champaign, Urbana, IL, USA (2008)
Hendrix, J., Clavel, M., Meseguer, J.: A Sufficient Completeness Reasoning Tool for Partial Specifications. In: Giesl, J. (ed.) RTA 2005. LNCS, vol. 3467, pp. 165–174. Springer, Heidelberg (2005)
Lucas, S., Marché, C., Meseguer, J.: Operational Termination of Conditional Term Rewriting Systems. Information Processing Letters 95(4), 446–453 (2005)
Meseguer, J.: Membership Algebra as a Logical Framework for Equational Specification. In: Parisi-Presicce, F. (ed.) WADT 1997. LNCS, vol. 1376, pp. 18–61. Springer, Heidelberg (1998)
Meseguer, J., Goguen, J.A.: Initially, Induction and Computability. Algebraic Methods in Semantics (1986)
Musser, D.R.: On Proving Inductive Properties of Abstract Data Types. In: Proc. of the 7th Annual ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages, POPL 1980, pp. 154–162. ACM Press (1980)
Masaki, N., Kokichi, F.: On Equality Predicates in Algebraic Specification Languages. In: Jones, C.B., Liu, Z., Woodcock, J. (eds.) ICTAC 2007. LNCS, vol. 4711, pp. 381–395. Springer, Heidelberg (2007)
Rocha, C., Meseguer, J.: Theorem Proving Modulo Based on Boolean Equational Procedures. In: Berghammer, R., Möller, B., Struth, G. (eds.) RelMiCS/AKA 2008. LNCS, vol. 4988, pp. 337–351. Springer, Heidelberg (2008)
Rocha, C., Meseguer, J.: Proving Safety Properties of Rewrite Theories. In: Corradini, A., Klin, B., Cîrstea, C. (eds.) CALCO 2011. LNCS, vol. 6859, pp. 314–328. Springer, Heidelberg (2011)
dc.rights.coar.fl_str_mv http://purl.org/coar/access_right/c_14cb
dc.rights.accessrights.spa.fl_str_mv info:eu-repo/semantics/closedAccess
eu_rights_str_mv closedAccess
rights_invalid_str_mv http://purl.org/coar/access_right/c_14cb
dc.format.extent.spa.fl_str_mv 20 páginas.
dc.format.mimetype.spa.fl_str_mv application/pdf
dc.publisher.spa.fl_str_mv Springer
dc.publisher.place.spa.fl_str_mv Berlin.
institution Escuela Colombiana de Ingeniería Julio Garavito
bitstream.url.fl_str_mv https://repositorio.escuelaing.edu.co/bitstream/001/1859/3/Order-Sorted%20Equality%20Enrichments%20Modulo%20Axioms.png
https://repositorio.escuelaing.edu.co/bitstream/001/1859/4/Order-Sorted%20Equality%20Enrichments%20Modulo%20Axioms.png.jpg
https://repositorio.escuelaing.edu.co/bitstream/001/1859/1/Order-Sorted%20Equality%20Enrichments%20Modulo%20Axioms.png
https://repositorio.escuelaing.edu.co/bitstream/001/1859/2/license.txt
bitstream.checksum.fl_str_mv d1d133d6370fc776634dd28eb905b678
b3cfb2d465b6323eedfaa1eb3a39827d
b28fadbd3a62d439751fefaa4b41c7a0
5a7ca94c2e5326ee169f979d71d0f06e
bitstream.checksumAlgorithm.fl_str_mv MD5
MD5
MD5
MD5
repository.name.fl_str_mv Repositorio Escuela Colombiana de Ingeniería Julio Garavito
repository.mail.fl_str_mv repositorio.eci@escuelaing.edu.co
_version_ 1814355626217701376
spelling Gutiérrez, Raúlc48f602a579aed48a42a3d36547c54cc600Meseguer, José6da02984a567cfba226ed9b8bf7c47c0600Rocha, Camilo649eba80a4c919beefa7d19955bc2950600Informática2021-11-27T16:01:46Z2021-11-27T16:01:46Z20129783642340055https://repositorio.escuelaing.edu.co/handle/001/1859Built-in equality and inequality predicates based on comparison of canonical forms in algebraic specifications are frequently used because they are handy and efficient. However, their use places algebraic specifications with initial algebra semantics beyond the pale of theorem proving tools based, for example, on explicit or inductionless induction techniques, and of other formal tools for checking key properties such as confluence, termination, and sufficient completeness. Such specifications would instead be amenable to formal analysis if an equationally-defined equality predicate enriching the algebraic data types were to be added to them. Furthermore, having an equationally-defined equality predicate is very useful in its own right, particularly in inductive theorem proving. Is it possible to effectively define a theory transformation E↦E≃ that extends an algebraic specification E to a specification E≃ having an equationally-defined equality predicate? This paper answers this question in the affirmative for a broad class of order-sorted conditional specifications E that are sort-decreasing, ground confluent, and operationally terminating modulo axioms B and have a subsignature of constructors. The axioms B can consist of associativity, or commutativity, or associativity-commutativity axioms, so that the constructors are free modulo B. We prove that the transformation E↦E≃ preserves all the just-mentioned properties of E . The transformation has been automated in Maude using reflection and is used in several Maude formal tools.Los predicados de igualdad y desigualdad incorporados basados ​​en la comparación de formas canónicas en especificaciones algebraicas se usan con frecuencia porque son prácticos y eficientes. Sin embargo, su uso sitúa las especificaciones algebraicas con semántica inicial del álgebra más allá de las herramientas de prueba de teoremas basadas, por ejemplo, en técnicas de inducción explícitas o sin inducción, y de otras herramientas formales para verificar propiedades clave como la confluencia, la terminación y la completitud suficiente. En cambio, tales especificaciones serían susceptibles de análisis formal si se les agregara un predicado de igualdad definido ecuacionalmente que enriqueciera los tipos de datos algebraicos. Además, tener un predicado de igualdad definido ecuacionalmente es muy útil por derecho propio, particularmente en la demostración inductiva de teoremas. ¿Es posible definir efectivamente una transformación teórica E↦E≃ que extienda una especificación algebraica E a una especificación E≃ que tenga un predicado de igualdad definido ecuacionalmente? Este artículo responde afirmativamente a esta pregunta para una amplia clase de especificaciones E condicionales clasificadas por orden que son de orden decreciente, confluentes en el suelo y que terminan operacionalmente los axiomas del módulo B y tienen una subfirma de constructores. Los axiomas B pueden consistir en axiomas de asociatividad, de conmutatividad o de asociatividad-conmutatividad, de modo que los constructores sean módulo B libre. Probamos que la transformación E↦E≃ conserva todas las propiedades de E recién mencionadas. La transformación se ha automatizado en Maude mediante reflexión y se utiliza en varias herramientas formales de Maude.20 páginas.application/pdfengSpringerBerlin.Lecture Notes in Computer Science book series (LNCS);7571N/ARewriting Logic and Its ApplicationsBaader, F., Nipkow, T.: Term Rewriting and All That. Cambridge University Press (1998)Bergstra, J., Tucker, J.: Characterization of Computable Data Types by Means of a Finite Equational Specification Method. In: de Bakker, J.W., van Leeuwen, J. (eds.) ICALP 1980. LNCS, vol. 81, pp. 76–90. Springer, Heidelberg (1980)Clavel, M., Durán, F., Eker, S., Lincoln, P., Martí-Oliet, N., Meseguer, J., Talcott, C.: All About Maude - A High-Performance Logical Framework. LNCS, vol. 4350. Springer, Heidelberg (2007)Durán, F., Lucas, S., Marché, C., Meseguer, J., Urbain, X.: Proving Operational Termination of Membership Equational Programs. Higher Order Symbolic Computation 21(1-2), 59–88 (2008)Durán, F., Lucas, S., Meseguer, J.: Termination Modulo Combinations of Equational Theories. In: Ghilardi, S., Sebastiani, R. (eds.) FroCoS 2009. LNCS, vol. 5749, pp. 246–262. Springer, Heidelberg (2009)Durán, F., Meseguer, J.: On the Church-Rosser and Coherence Properties of Conditional Order-Sorted Rewrite Theories. Journal of Logic and Algebraic Programming (2011) (to appear)Goguen, J., Meseguer, J.: Order-Sorted Algebra I: Equational Deduction for Multiple Inheritance, Overloading, Exceptions and Partial Operations. Theoretical Computer Science 105, 217–273 (1992)Goguen, J.A.: How to Prove Algebraic Inductive Hypotheses Without Induction. In: Bibel, W., Kowalski, R. (eds.) CADE 1980. LNCS, vol. 87, pp. 356–373. Springer, Heidelberg (1980)Gutiérrez, R., Meseguer, J., Rocha, C.: Order-Sorted Equality Enrichments Modulo Axioms (Extended Version). Tech. rep., University of Illinois at Urbana-Champaing (December 2011), http://hdl.handle.net/2142/28597Hendrix, J.: Decision Procedures for Equationally Based Reasoning. Ph.D. thesis, Department of Computer Science, University of Illinois at Urbana-Champaign, Urbana, IL, USA (2008)Hendrix, J., Clavel, M., Meseguer, J.: A Sufficient Completeness Reasoning Tool for Partial Specifications. In: Giesl, J. (ed.) RTA 2005. LNCS, vol. 3467, pp. 165–174. Springer, Heidelberg (2005)Lucas, S., Marché, C., Meseguer, J.: Operational Termination of Conditional Term Rewriting Systems. Information Processing Letters 95(4), 446–453 (2005)Meseguer, J.: Membership Algebra as a Logical Framework for Equational Specification. In: Parisi-Presicce, F. (ed.) WADT 1997. LNCS, vol. 1376, pp. 18–61. Springer, Heidelberg (1998)Meseguer, J., Goguen, J.A.: Initially, Induction and Computability. Algebraic Methods in Semantics (1986)Musser, D.R.: On Proving Inductive Properties of Abstract Data Types. In: Proc. of the 7th Annual ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages, POPL 1980, pp. 154–162. ACM Press (1980)Masaki, N., Kokichi, F.: On Equality Predicates in Algebraic Specification Languages. In: Jones, C.B., Liu, Z., Woodcock, J. (eds.) ICTAC 2007. LNCS, vol. 4711, pp. 381–395. Springer, Heidelberg (2007)Rocha, C., Meseguer, J.: Theorem Proving Modulo Based on Boolean Equational Procedures. In: Berghammer, R., Möller, B., Struth, G. (eds.) RelMiCS/AKA 2008. LNCS, vol. 4988, pp. 337–351. Springer, Heidelberg (2008)Rocha, C., Meseguer, J.: Proving Safety Properties of Rewrite Theories. In: Corradini, A., Klin, B., Cîrstea, C. (eds.) CALCO 2011. LNCS, vol. 6859, pp. 314–328. Springer, Heidelberg (2011)Order-Sorted Equality Enrichments Modulo AxiomsCapítulo - Parte de Libroinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_3248http://purl.org/coar/resource_type/c_2df8fbb1Textinfo:eu-repo/semantics/bookParthttp://purl.org/redcol/resource_type/ARThttp://purl.org/coar/version/c_970fb48d4fbd8a85info:eu-repo/semantics/closedAccesshttp://purl.org/coar/access_right/c_14cbTeoría EcuacionalObligación de pruebaTransformación de la teoríaEspecificación algebraicaÁlgebra InicialEquational TheoryProof ObligationTheory TransformationAlgebraic SpecificationInitial AlgebraTHUMBNAILOrder-Sorted Equality Enrichments Modulo Axioms.pngOrder-Sorted Equality Enrichments Modulo Axioms.pngimage/png125067https://repositorio.escuelaing.edu.co/bitstream/001/1859/3/Order-Sorted%20Equality%20Enrichments%20Modulo%20Axioms.pngd1d133d6370fc776634dd28eb905b678MD53open accessOrder-Sorted Equality Enrichments Modulo Axioms.png.jpgOrder-Sorted Equality Enrichments Modulo Axioms.png.jpgGenerated Thumbnailimage/jpeg4164https://repositorio.escuelaing.edu.co/bitstream/001/1859/4/Order-Sorted%20Equality%20Enrichments%20Modulo%20Axioms.png.jpgb3cfb2d465b6323eedfaa1eb3a39827dMD54open accessORIGINALOrder-Sorted Equality Enrichments Modulo Axioms.pngOrder-Sorted Equality Enrichments Modulo Axioms.pngimage/png29134https://repositorio.escuelaing.edu.co/bitstream/001/1859/1/Order-Sorted%20Equality%20Enrichments%20Modulo%20Axioms.pngb28fadbd3a62d439751fefaa4b41c7a0MD51open accessLICENSElicense.txtlicense.txttext/plain; charset=utf-81881https://repositorio.escuelaing.edu.co/bitstream/001/1859/2/license.txt5a7ca94c2e5326ee169f979d71d0f06eMD52open access001/1859oai:repositorio.escuelaing.edu.co:001/18592022-12-13 03:01:46.895open accessRepositorio Escuela Colombiana de Ingeniería Julio Garavitorepositorio.eci@escuelaing.edu.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