33 research outputs found
Variant-Based Decidable Satisfiability in Initial Algebras with Predicates
[EN] Decision procedures can be either theory-specific, e.g., Presburger arithmetic, or theory-generic, applying to an infinite number of user-definable theories. Variant satisfiability is a theory-generic procedure for quantifier-free satisfiability in the initial algebra of an order-sorted equational theory (Âż,EÂżB) under two conditions: (i) EÂżB has the finite variant property and B has a finitary unification algorithm; and (ii) (Âż,EÂżB) protects a constructor subtheory (Âż,E¿¿BÂż) that is OS-compact. These conditions apply to many user-definable theories, but have a main limitation: they apply well to data structures, but often do not hold for user-definable predicates on such data structures. We present a theory-generic satisfiability decision procedure, and a prototype implementation, extending variant-based satisfiability to initial algebras with user-definable predicates under fairly general conditions.Partially supported by NSF Grant CNS 14-09416, NRL under contract number N00173-17-1-G002, the EU (FEDER), Spanish MINECO project TIN2015-69175- C4-1-R and GV project PROMETEOII/2015/013. RaÂŽul GutiÂŽerrez was also supported by INCIBE program âAyudas para la excelencia de los equipos de investigaciÂŽon avanzada en ciberseguridadâ.GutiĂ©rrez Gil, R.; Meseguer, J. (2018). Variant-Based Decidable Satisfiability in Initial Algebras with Predicates. Lecture Notes in Computer Science. 10855:306-322. https://doi.org/10.1007/978-3-319-94460-9_18S30632210855Armando, A., Bonacina, M.P., Ranise, S., Schulz, S.: New results on rewrite-based satisfiability procedures. TOCL 10(1), 4 (2009)Armando, A., Ranise, S., Rusinowitch, M.: A rewriting approach to satisfiability procedures. I&C 183(2), 140â164 (2003)Barrett, C., Shikanian, I., Tinelli, C.: An abstract decision procedure for satisfiability in the theory of inductive data types. JSAT 3, 21â46 (2007)Bouchard, C., Gero, K.A., Lynch, C., Narendran, P.: On forward closure and the finite variant property. In: Fontaine, P., Ringeissen, C., Schmidt, R.A. (eds.) FroCoS 2013. LNCS (LNAI), vol. 8152, pp. 327â342. Springer, Heidelberg (2013). https://doi.org/10.1007/978-3-642-40885-4_23Bradley, A.R., Manna, Z.: The Calculus of Computation - Decision Procedures with Applications to Verification. Springer, Heidelberg (2007). https://doi.org/10.1007/978-3-540-74113-8Cholewa, A., Meseguer, J., Escobar, S.: Variants of variants and the finite variant property. Technical report, CS Dept. University of Illinois at Urbana-Champaign (2014). http://hdl.handle.net/2142/47117Ciobaca., S.: Verification of composition of security protocols with applications to electronic voting. Ph.D. thesis, ENS Cachan (2011)Comon, H.: Complete axiomatizations of some quotient term algebras. TCS 118(2), 167â191 (1993)Comon-Lundh, H., Delaune, S.: The finite variant property: how to get rid of some algebraic properties. In: Giesl, J. (ed.) RTA 2005. LNCS, vol. 3467, pp. 294â307. Springer, Heidelberg (2005). https://doi.org/10.1007/978-3-540-32033-3_22Dershowitz, N., Jouannaud, J.P.: Rewrite systems. In: Handbook of Theoretical Computer Science, North-Holland, vol. B, pp. 243â320 (1990)Dovier, A., Piazza, C., Rossi, G.: A uniform approach to constraint-solving for lists, multisets, compact lists, and sets. TOCL 9(3), 15 (2008)Dross, C., Conchon, S., Kanig, J., Paskevich, A.: Adding decision procedures to SMT solvers using axioms with triggers. JAR 56(4), 387â457 (2016)Escobar, S., Sasse, R., Meseguer, J.: Folding variant narrowing and optimal variant termination. JALP 81, 898â928 (2012)Goguen, J.A., Meseguer, J.: Models and equality for logical programming. In: Ehrig, H., Kowalski, R., Levi, G., Montanari, U. (eds.) TAPSOFT 1987. LNCS, vol. 250, pp. 1â22. Springer, Heidelberg (1987). https://doi.org/10.1007/BFb0014969Goguen, J., Meseguer, J.: Order-sorted algebra I: equational deduction for multiple inheritance, overloading, exceptions and partial operations. TCS 105, 217â273 (1992)GutiĂ©rrez, R., Meseguer, J.: Variant satisfiability in initial algebras with predicates. Technical report, CS Department, University of Illinois at Urbana-Champaign (2018). http://hdl.handle.net/2142/99039Jouannaud, J.P., Kirchner, H.: Completion of a set of rules modulo a set of equations. SICOMP 15, 1155â1194 (1986)Kroening, D., Strichman, O.: Decision Procedures - An algorithmic point of view. Texts in TCS. An EATCS Series. Springer, Heidelberg (2008). https://doi.org/10.1007/978-3-540-74105-3Lynch, C., Morawska, B.: Automatic decidability. In: Proceedings of LICS 2002, p. 7. IEEE Computer Society (2002)Lynch, C., Tran, D.-K.: Automatic decidability and combinability revisited. In: Pfenning, F. (ed.) CADE 2007. LNCS (LNAI), vol. 4603, pp. 328â344. Springer, Heidelberg (2007). https://doi.org/10.1007/978-3-540-73595-3_22Meseguer, J.: Variant-based satisfiability in initial algebras. SCP 154, 3â41 (2018)Meseguer, J.: Strict coherence of conditional rewriting modulo axioms. TCS 672, 1â35 (2017)Meseguer, J., Goguen, J.: Initiality, induction and computability. In: Algebraic Methods in Semantics, Cambridge, pp. 459â541 (1985)Meseguer, J., Goguen, J.: Order-sorted algebra solves the constructor-selector, multiple representation and coercion problems. I&C 103(1), 114â158 (1993)Nelson, G., Oppen, D.C.: Simplification by cooperating decision procedures. TOPLAS 1(2), 245â257 (1979)Shostak, R.E.: Deciding combinations of theories. J. ACM 31(1), 1â12 (1984)Skeirik, S., Meseguer, J.: Metalevel algorithms for variant satisfiability. In: Lucanu, D. (ed.) WRLA 2016. LNCS, vol. 9942, pp. 167â184. Springer, Cham (2016). https://doi.org/10.1007/978-3-319-44802-2_10Stump, A., Barrett, C.W., Dill, D.L., Levitt, J.R.: A decision procedure for an extensional theory of arrays. In: Proceedings of LICS 2001, pp. 29â37. IEEE (2001)Tushkanova, E., Giorgetti, A., Ringeissen, C., Kouchnarenko, O.: A rule-based system for automatic decidability and combinability. SCP 99, 3â23 (2015
Metalevel algorithms for variant satisfiability
Variant satisïŹability is a theory-generic algorithm to decide quantiïŹer-free satisïŹability in an initial algebra when its corresponding theory has the ïŹnite variant property and its constructors satisfy a compactness condition. This paper: (i) gives a precise definition of several meta-level sub-algorithms needed for variant satisïŹability; (ii) proves them correct; and (iii) presents a reflective implementation in Maude 2.7 of variant satisïŹability using these sub-algorithms.NSF CNS 13-19109Ope
Unification modulo Lists with Reverse, Relation with Certain Word Equations
International audienceDecision procedures for various list theories have been investigated in the literature with applications to automated verification. Here we show that the unifiability problem for some list theories with a \emph{reverse} operator is NP-complete. We also give a unifiability algorithm for the case where the theories are extended with a \emph{length} operator on lists
HIV-1 Vpr-Induced Apoptosis Is Cell Cycle Dependent and Requires Bax but Not ANT
The HIV-1 accessory protein viral protein R (Vpr) causes G(2) arrest and apoptosis in infected cells. We previously identified the DNA damageâsignaling protein ATR as the cellular factor that mediates Vpr-induced G(2) arrest and apoptosis. Here, we examine the mechanism of induction of apoptosis by Vpr and how it relates to induction of G(2) arrest. We find that entry into G(2) is a requirement for Vpr to induce apoptosis. We investigated the role of the mitochondrial permeability transition pore by knockdown of its essential component, the adenine nucleotide translocator. We found that Vpr-induced apoptosis was unaffected by knockdown of ANT. Instead, apoptosis is triggered through a different mitochondrial pore protein, Bax. In support of the idea that checkpoint activation and apoptosis induction are functionally linked, we show that Bax activation by Vpr was ablated when ATR or GADD45α was knocked down. Certain mutants of Vpr, such as R77Q and I74A, identified in long-term nonprogressors, have been proposed to inefficiently induce apoptosis while activating the G(2) checkpoint in a normal manner. We tested the in vitro phenotypes of these mutants and found that their abilities to induce apoptosis and G(2) arrest are indistinguishable from those of HIV-1(NL4â3) vpr, providing additional support to the idea that G(2) arrest and apoptosis induction are mechanistically linked
Protocol of the baseline assessment for the Environments for Healthy Living (EHL) Wales cohort study
Background
Health is a result of influences operating at multiple levels. For example, inadequate housing, poor educational attainment, and reduced access to health care are clustered together, and are all associated with reduced health. Policies which try to change individual people's behaviour have limited effect when people have little control over their environment. However, structural environmental change and an understanding of the way that influences interact with each other, has the potential to facilitate healthy choices irrespective of personal resources. The aim of Environments for Healthy Living (EHL) is to investigate the impact of gestational and postnatal environments on health, and to examine where structural change can be brought about to optimise health outcomes. The baseline assessment will focus on birth outcomes and maternal and infant health.
Methods/Design
EHL is a longitudinal birth cohort study. We aim to recruit 1000 pregnant women in the period April 2010 to March 2013. We will examine the impact of the gestational environment (maternal health) and the postnatal environment (housing and neighbourhood conditions) on subsequent health outcomes for the infants born to these women. Data collection will commence during the participants' pregnancy, from approximately 20 weeks gestation. Participants will complete a questionnaire, undergo anthropometric measurements, wear an accelerometer, compile a food diary, and have environmental measures taken within their home. They will also be asked to consent to having a sample of umbilical cord blood taken following delivery of their baby. These data will be complemented by routinely collected electronic data such as health records from GP surgeries, hospital admissions, and child health and development records. Thereafter, participants will be visited annually for follow-up of subsequent exposures and child health outcomes.
Discussion
The baseline assessment of EHL will provide information concerning the impact of gestational and postnatal environments on birth outcomes and maternal and infant health. The findings can be used to inform the development of complex interventions targeted at structural, environmental factors, intended to reduce ill-health. Long-term follow-up of the cohort will focus on relationships between environmental exposures and the later development of adverse health outcomes, including obesity and diabetes