Equational Formulas and Pattern Operations in Initial Order-Sorted Algebras

A pattern, i.e., a term possibly with variables, denotes the set (language) of all its ground instances. In an untyped setting, symbolic operations on finite sets of patterns can represent Boolean operations on languages. But for the more expressive patterns needed in declarative languages supporting rich type disciplines such as subtype polymorphism untyped pattern operations and algorithms break down. We show how they can be properly defined by means of a signature transformation that enriches the types of the original signature. We also show that this transformation allows a systematic reduction of the first-order logic properties of an initial order-sorted algebra supporting subtype-polymorphic functions to equivalent properties of an initial many-sorted (i.e., simply typed) algebra. This yields a new, simple proof of the known decidability of the first-order theory of an initial order-sorted algebra.Partially supported by NSF Grant CNS 13-19109.Ope

Automatic Synthesis of Logical Models for Order-Sorted First-Order Theories

[EN] In program analysis, the synthesis of models of logical theories representing the program semantics is often useful to prove program properties. We use order-sorted first- order logic as an appropriate framework to describe the semantics and properties of programs as given theories. Then we investigate the automatic synthesis of models for such theories. We use convex polytopic domains as a flexible approach to associate different domains to different sorts. We introduce a framework for the piecewise definition of functions and predicates. We develop its use with linear expressions (in a wide sense, including linear transformations represented as matrices) and inequalities to specify functions and predicates. In this way, algorithms and tools from linear algebra and arithmetic constraint solving (e.g., SMT) can be used as a backend for an efficient implementation.Partially supported by the EU (FEDER), projects TIN2015-69175-C4-1-R, and GV PROMETEOII/2015/ 013. R. Gutiérrez also supported by Juan de la Cierva Fellowship JCI-2012-13528.Lucas Alba, S.; Gutiérrez Gil, R. (2018). Automatic Synthesis of Logical Models for Order-Sorted First-Order Theories. Journal of Automated Reasoning. 60(4):465-501. https://doi.org/10.1007/s10817-017-9419-3S465501604Alarcón, B., Gutiérrez, R., Lucas, S., Navarro-Marset, R.: Proving termination properties with MU-TERM. In: Proceedings of AMAST’10. LNCS, vol. 6486, pp. 201–208 (2011)Alarcón, B., Lucas, S., Navarro-Marset, R.: Using matrix interpretations over the reals in proofs of termination. In: Proceedings of PROLE’09, pp. 255–264 (2009)Albert, E., Genaim, S., Gutiérrez, R.: A Transformational Approach to Resource Analysis with Typed-Norms. Revised Selected Papers from LOPSTR’13. LNCS, vol. 8901, pp 38–53 (2013)de Angelis, E., Fioravante, F., Pettorossi, A., Proietti, M.: Proving correctness of imperative programs by linearizing constrained Horn clauses. Theory Pract. Log. Program. 15(4–5), 635–650 (2015)de Angelis, E., Fioravante, F., Pettorossi, A., Proietti, M.: Semantics-based generation of verification conditions by program specialization. In: Proceedings of PPDP’15, pp. 91–102. ACM Press, New York (2015)Aoto, T.: Solution to the problem of zantema on a persistent property of term rewriting systems. J. Funct. Log. Program. 2001(11), 1–20 (2001)Barwise, J.: An Introduction to First-Order Logic. In: Barwise, J. (ed.) Handbook of Mathematical Logic. North-Holland, Amsterdam (1977)Barwise, J.: Axioms for Abstract Model Theory. Ann. Math. Log. 7, 221–265 (1974)Bochnak, J., Coste, M., Roy, M.-F.: Real Algebraic Geometry. Springer, Berlin (1998)Birkhoff, G., Lipson, J.D.: Heterogeneous algebras. J. Comb. Theory 8, 115–133 (1970)Bofill, M., Nieuwenhuis, R., Oliveras, A., Rodríguez-Carbonell, E., Rubio, A.: The Barcelogic SMT Solver. In: Proceedings of CAV’08. LNCS, vol. 5123, pp. 294–298 (2008)Bjørner, N., Gurfinkel, A., McMillan, K., Rybalchenko, A.: Horn-clause solvers for program verification. In: Fields of Logic and Computation II—Essays Dedicated to Yuri Gurevich on the Occasion of His 75th Birthday. LNCS, vol. 9300, pp. 24–51 (2015)Bjørner, N., McMillan, K., Rybalchenko, A.: On solving universally quantified horn-clauses. In: Proceedings of SAS’13. LNCS vol. 7935, pp. 105–125 (2013)Bjørner, N., McMillan, K., Rybalchenko, A.: Program verification as satisfiability modulo theories. In: Proceedings of SMT’12, EPiC Series in Computing, vol. 20, pp. 3–11 (2013)Bliss, G.A.: Algebraic Functions. Dover (2004)Bonfante, G., Marion, J.-Y., Moyen, J.-Y.: On Lexicographic Termination Ordering With Space Bound Certifications. Revised Papers from PSI 2001. LNCS, vol. 2244, pp. 482–493 (2001)Boolos, G.S., Burgess, J.P., Jeffrey, R.C.: Computability and Logic, 4th edn. Cambridge University Press, Cambridge (2002)Borralleras, C., Lucas, S., Oliveras, A., Rodríguez, E., Rubio, A.: SAT modulo linear arithmetic for solving polynomial constraints. J. Autom. Reason. 48, 107–131 (2012)Bürckert, H.-J., Hollunder, B., Laux, A.: On Skolemization in constrained logics. Ann. Math. Artif. Intell. 18, 95–131 (1996)Burstall, R.M., Goguen, J.A.: Putting Theories together to make specifications. In: Proceedings of IJCAI’77, pp. 1045–1058. William Kaufmann (1977)Caplain, M.: Finding invariant assertions for proving programs. In: Proceedings of the International Conference on Reliable Software, pp. 165–171. ACM Press, New York (1975)Chang, C.L., Lee, R.C.: Symbolic Logic and Mechanical Theorem Proving. Academic Press, Orlando (1973)Clavel, M., Durán, F., Eker, S., Lincoln, P., Martí-Oliet, N., Meseguer, J., Talcott, C.: All About Maude—A High-Performance Logical Framework. LNCS 4350, (2007)Cohn, A.G.: Improving the expressiveness of many sorted logic. In: Proceedings of the National Conference on Artificial Intelligence, pp. 84–87. AAAI Press, Menlo Park (1983)Contejean, E., Marché, C., Tomás, A.-P., Urbain, X.: Mechanically proving termination using polynomial interpretations. J. Autom. Reason. 34(4), 325–363 (2006)Cooper, D.C.: Programs for mechanical program verification. Mach. Intell. 6, 43–59 (1971). Edinburgh University PressCooper, D.C.: Theorem proving in arithmetic without multiplication. Mach. Intell. 7, 91–99 (1972)Courtieu, P., Gbedo, G., Pons, O.: Improved matrix interpretations. In: Proceedings of SOFSEM’10. LNCS, vol. 5901, pp. 283–295 (2010)Cousot, P., Cousot, R., Mauborgne, L.: Logical abstract domains and interpretations. In: The Future of Sofware Engineering, pp. 48–71. Springer, New York (2011)Cousot, P., Halbwachs, N.: Automatic Discovery of linear restraints among variables of a program. In: Conference Record of POPL’78, pp. 84–96. ACM Press, New York (1978)Davey, B.A., Priestley, H.A.: Introduction to Lattices and Order. Cambridge University Press, Cambridge (1990)Elspas, B., Levitt, K.N., Waldinger, R.J., Waksman, A.: An assessment of techniques for proving program correctness. Comput. Surv. 4(2), 97–147 (1972)van Emdem, M.H., Kowalski, R.A.: The semantics of predicate logic as a programming language. J. ACM 23(4), 733–742 (1976)Endrullis, J., Waldmann, J., Zantema, H.: Matrix interpretations for proving termination of term rewriting. In: Proceedings of IJCAR’06. LNCS, vol. 4130, pp. 574–588 (2006)Endrullis, J., Waldmann, J., Zantema, H.: Matrix interpretations for proving termination of term rewriting. J. Autom. Reason. 40(2–3), 195–220 (2008)Floyd, R.W.: Assigning meanings to programs. Math. Asp. Comput. Sci. 19, 19–32 (1967)Fuhs, C., Giesl, J., Middeldorp, A., Schneider-Kamp, P., Thiemann, R., Zankl, H.: Maximal termination. In: Proceedings of RTA’08. LNCS, vol. 5117, pp. 110–125 (2008)Fuhs, C., Giesl, J., Parting, M., Schneider-Kamp, P., Swiderski, S.: Proving termination by dependency pairs and inductive theorem proving. J. Autom. Reason. 47, 133–160 (2011)Fuhs, C., Kop, C.: Polynomial interpretations for higher-order rewriting. In: Proceedings of RTA’12. LIPIcs, vol. 15, pp. 176–192 (2012)Futatsugi, K., Diaconescu, R.: CafeOBJ Report. World Scientific, AMAST Series, (1998)Gaboardi, M., Péchoux, R.: On bounding space usage of streams using interpretation analysis. Sci. Comput. Program. 111, 395–425 (2015)Giesl, J., Mesnard, F., Rubio, A., Thiemann, R., Waldmann, J.: Termination competition (termCOMP 2015). In: Proceedings of CADE’15. LNCS, vol. 9195, pp. 105–108 (2015)Giesl, J., Ströder, T., Schneider-Kamp, P., Emmes, F., Fuhs, C.: Symbolic evaluation graphs and term rewriting—a general methodology for analyzing logic programs. In: Proceedings of the PPDP’12, pp. 1–12. ACM Press (2012)Giesl, J., Raffelsieper, M., Schneider-Kamp, P., Swiderski, S., Thiemann, R.: Automated termination proofs for haskell by term rewriting. ACM Trans. Program. Lang. Syst. 33(2), 7 (2011)Gnaedig, I.: Termination of Order-sorted Rewriting. In: Proceedings of ALP’92. LNCS, vol. 632, pp. 37–52 (1992)Goguen, J.A.: Order-Sorted Algebra. Semantics and Theory of Computation Report 14, UCLA (1978)Goguen, J.A., Burstall, R.M.: Some fundamental algebraic tools for the semantics of computation. Part 1: comma categories, colimits, signatures and theories. Theoret. Comput. Sci. 31, 175–209 (1984)Goguen, J.A., Burstall, R.M.: Some fundamental algebraic tools for the semantics of computation. Part 2 signed and abstract theories. Theoret. Comput. Sci. 31, 263–295 (1984)Goguen, J., Meseguer, J.: Models and equality for logical programming. In: Proceedings of TAPSOFT’87. LNCS, vol. 250, pp. 1–22 (1987)Goguen, J.A., Thatcher, J.W., Wagner, E.G.: An initial algebra approach to the specification, correctness and implementation of abstract data types. In: Current Trends in Programming Methodology, pp. 80–149. Prentice Hall (1978)Goguen, J.A., Meseguer, J.: Remarks on remarks on many-sorted equational logic. Sigplan Notices 22(4), 41–48 (1987)Goguen, J., Meseguer, J.: Order-sorted algebra I: equational deduction for multiple inheritance, overloading, exceptions and partial operations. Theoret. Comput. Sci. 105, 217–273 (1992)Goguen, J.A., Winkler, T., Meseguer, J., Futatsugi, K., Jouannaud, J.-P.: Introducing OBJ. In: Goguen, J., Malcolm, G. (eds.) Software Engineering with OBJ: Algebraic Specification in Action. Kluwer, Boston (2000)Grebenshikov, S., Lopes, N.P., Popeea, C., Rybalchenko, A.: Synthesizing software verifiers from proof rules. In: Proceedings of PLDI’12, pp. 405–416. ACM Press (2012)Gulwani, S., Tiwari, A.: Combining Abstract Interpreters. In: Proceedings of PLDI’06, pp. 376–386. ACM Press (2006)Gurfinkel, A., Kahsai, T., Komuravelli, A., Navas, J.A.: The seahorn verification framework. In: Proceedings of CAV’15, Part I. LNCS, vol. 9206, pp. 343–361 (2015)Gutiérrez, R., Lucas, S., Reinoso, P.: A tool for the automatic generation of logical models of order-sorted first-order theories. In: Proceedings of PROLE’16, pp. 215–230 (2016). http://zenon.dsic.upv.es/ages/Hantler, S.L., King, J.C.: An introduction to proving the correctness of programs. ACM Comput. Surv. 8(3), 331–353 (1976)Hayes, P.: A logic of actions. Mach. Intell. 6, 495–520 (1971). Edinburgh University Press, EdinburghHeidergott, B., Olsder, G.J., van der Woude, J.: Max plus at work. A course on max-plus algebra and its applications. In: Modeling and Analysis of Synchronized Systems, Princeton University Press (2006)Hirokawa, N., Moser, G.: Automated complexity analysis based on the dependency pair method. In: Proceedings of IJCAR 2008. LNCS, vol. 5195, pp. 364–379 (2008)Hoare, C.A.R.: An axiomatic basis for computer programming. Commun. ACM 12(10), 576–583 (1969)Hodges, W.: Elementary Predicate Logic. Handbook of Philosophical Logic, vol. 1, pp. 1–131. Reidel Publishing Company (1983)Hodges, W.: A Shorter Model Theory. Cambridge University Press, Cambridge (1997)Hofbauer, D.: Termination proofs by context-dependent interpretation. In: Proceedings of RTA’01. LNCS, vol. 2051, pp. 108–121 (2001)Hofbauer, D.: Termination proofs for ground rewrite systems. interpretations and derivational complexity. Appl. Algebra Eng. Commun. Comput. 12, 21–38 (2001)Hofbauer, D., Lautemann, C.: Termination proofs and the length of derivations. In: Proceedings of RTA’89. LNCS, vol. 355, pp. 167–177 (1989)Hull, T.E., Enright, W.H., Sedgwick, A.E.: The correctness of numerical algorithms. In: Proceedings of PAAP’72, pp. 66–73 (1972)Igarashi, S., London, R.L., Luckham, D.: Automatic program verification I: a logical basis and its implementation. Acta Inform. 4, 145–182 (1975)Iwami, M.: Persistence of termination of term rewriting systems with ordered sorts. In: Proceedings of 5th JSSST Workshop on Programming and Programming Languages, Shizuoka, Japan, pp. 47–56. (2003)Iwami, M.: Persistence of termination for non-overlapping term rewriting systems. In: Proceedings of Algebraic Systems, Formal Languages and Conventional and Unconventional Computation Theory, Kokyuroku RIMS, University of Kyoto, vol. 1366, pp. 91–99 (2004)Katz, S., Manna, Z.: Logical analysis of programs. Commun. ACM 19(4), 188–206 (1976)Langford, C.H.: Review: Über deduktive Theorien mit mehreren Sorten von Grunddingen. J. Symb. Log. 4(2), 98 (1939)Lankford, D.S.: Some approaches to equality for computational logic: a survey and assessment. Memo ATP-36, Automatic Theorem Proving Project, University of Texas, Austin, TXLondon, R.L.: The current state of proving programs correct. In: Proceedings of ACM’72, vol. 1, pp. 39–46. ACM (1972)Lucas, S.: Polynomials over the reals in proofs of termination: from theory to practice. RAIRO Theor. Inform. Appl. 39(3), 547–586 (2005)Lucas, S.: Synthesis of models for order-sorted first-order theories using linear algebra and constraint solving. Electron. Proc. Theor. Comput. Sci. 200, 32–47 (2015)Lucas, S.: Use of logical models for proving operational termination in general logics. In: Selected Papers from WRLA’16. LNCS, vol. 9942, pp. 1–21 (2016)Lucas, S., Marché, C., Meseguer, J.: Operational termination of conditional term rewriting systems. Inform. Proces. Lett. 95, 446–453 (2005)Lucas, S., Meseguer, J.: Models for logics and conditional constraints in automated proofs of termination. In: Proceedings of AISC’14. LNAI, vol. 8884, pp. 7–18 (2014)Lucas, S., Meseguer, J.: Order-sorted dependency pairs. In: Proceedings of PPDP’08 , pp. 108–119. ACM Press (2008)Lucas, S., Meseguer, J.: Proving operational termination of declarative programs in general logics. In: Proceedings of PPDP’14, pp. 111–122. ACM Digital Library (2014)Lucas, S., Meseguer, J.: Dependency pairs for proving termination properties of conditional term rewriting systems. J. Log. Algebr. Methods Program. 86, 236–268 (2017)Manna, Z.: The correctness of programs. J. Comput. Syst. Sci. 3, 119–127 (1969)Manna, Z.: Properties of programs and the first-order predicate calculus. J. ACM 16(2), 244–255 (1969)Manna, Z.: Termination of programs represented as interpreted graphs. In: Proceedings of AFIPS’70, pp. 83–89 (1970)Manna, Z., Ness, S.: On the termination of Markov algorithms. In: Proceedings of the Third Hawaii International Conference on System Science, pp. 789–792 (1970)Manna, Z., Pnueli, A.: Formalization of properties of functional programs. J. ACM 17(3), 555–569 (1970)Marion, Y.-I., Péchoux, R.: Sup-interpretations, a semantic method for static analysis of program resources. ACM Trans. Comput. Log. 10(4), 27 (2009)Martí-Oliet, N., Meseguer, J., Palomino, M.: Theoroidal maps as algebraic simulations. Revised Selected Papers from WADT’04. LNCS, vol. 3423, pp. 126–143 (2005)McCarthy, J.: Recursive functions of symbolic expressions and their computation by machine. Part I. Commun. ACM 3(4), 184–195 (1960)Meseguer, J.: General logics. In: Ebbinghaus, H.D., et al. (eds.) Logic Colloquium’87, pp. 275–329. North-Holland (1989)Meseguer, J., Skeirik, S.: Equational formulas and pattern operations in initial order-sorted algebras. Revised Selected Papers from LOPSTR’15. LNCS, vol. 9527, pp. 36–53 (2015)Middeldorp, A.: Matrix interpretations for polynomial derivational complexity of rewrite systems. In: Proceedings of LPAR’12. LNCS, vol. 7180, p. 12 (2012)Monin, J.-F.: Understanding Formal Methods. Springer, London (2003)Montenegro, M., Peña, R., Segura, C.: Space consumption analysis by abstract interpretation: inference of recursive functions. Sci. Comput. Program. 111, 426–457 (2015)de Moura, L., Bjørner, N.: Satisfiability modulo theories: introduction and applications. Commun. ACM 54(9), 69–77 (2011)Naur, P.: Proof of algorithms by general snapshots. Bit 6, 310–316 (1966)Neurauter, F., Middeldorp, A.: Revisiting matrix interpretations for proving termination of term rewriting. In: Proceedings of RTA’11. LIPICS, vol. 10, pp. 251–266 (2011)Ohlebusch, E.: Advanced Topics in Term Rewriting. Springer, New York (2002)Ölveczky, P.C., Lysne, O.: Order-sorted termination: the unsorted way. In: Proceedings of ALP’96. LNCS, vol. 1139, pp. 92–106 (1996)Otto, C., Brockschmidt, M., von Essen, C., Giesl, J.: Automated termination analysis of java bytecode by term rewriting. In: Proceedings of RTA’10. LIPICS, vol. 6, pp. 259–276 (2010)Péchoux, R.: Synthesis of sup-interpretations: a survey. Theoret. Comput. Sci. 467, 30–52 (2013)Podelski, A., Rybalchenko, A.: Transition invariants. In: IEEE Computer Society Proceedings of LICS’04, pp. 32–41 (2004)Prestel, A., Delzell, C.N.: Positive Polynomials. From Hilbert’s 17th Problem to Real Algebra. Springer, Berlin (2001)Robinson, D.J.S.: A Course in Linear Algebra with Applications, 2nd edn. World Scientific Publishing, Co, Singapore (2006)Rümmer, P., Hojjat, H., Kuncak, V.: Disjunctive interpolants for horn-clause verification. In: Proceedings of CAV’13, vol. 8044, pp. 347–363 (2013)Schrijver, A.: Theory of Linear and Integer Programming. Wiley, Amsterdam (1986)Schmidt, A.: Über deduktive Theorien mit mehreren Sorten von Grunddingen. Matematische Annalen 115(4), 485–506 (1938)Schmidt-Schauss, M.: Computational Aspects Of An Order-Sorted Logic With Term Declarations. PhD Thesis, Fachbereich Informatik der Universität Kaiserslautern (1988)Shapiro, S.: Foundations without Foundationalism: A Case for Second-Order Logic. Clarendon Press, New York (1991)Shostak, R.E.: A practical decision procedure for arithmetic with function symbols. J. ACM 26(2), 351–360 (1979)Smullyan, R.M.: Theory of Formal Systems. Princeton University Press, Princeton (1961)Tarski, A.: A Decision Method for Elementary Algebra and Geometry, 2nd edn. University of California Press, Berkeley (1951)Toyama, Y.: Counterexamples to termination for the direct sum of term rewriting systems. Inform. Process. Lett. 25, 141–143 (1987)Turing, A.M.: Checking a large routine. In: Report of a Conference on High Speed Automatic Calculating Machines, University Mathematics Laboratory, Cambridge, pp. 67–69 (1949)Urban, C.: The abstract domain of segmented ranking functions. In: Proceeding of SAS’13. LNCS, vol. 7935, pp. 43–62 (2013)Urban, C., Gurfinkel, A., Kahsai, T.: Synthesizing ranking functions from bits and pieces. In: Proceedings of TACAS’16. LNCS, vol. 9636, pp. 54–70 (2016)Waldmann, J.: Matrix interpretations on polyhedral domains. In: Proceedings of RTA’15. LIPICS, vol. 26, pp. 318–333 (2015)Waldmann, J., Bau, A., Noeth, E.: Matchbox termination prover. http://github.com/jwaldmann/matchbox/ (2014)Walther, C.: A mechanical solution of schubert’s steamroller by many-sorted resolution. Aritif. Intell. 26, 217–224 (1985)Wang, H.: Logic of many-sorted theories. J. Symb. Logic 17(2), 105–116 (1952)Zantema, H.: Termination of term rewriting: interpretation and type elimination. J. Symb. Comput. 17, 23–50 (1994

Matching Logic

This paper presents matching logic, a first-order logic (FOL) variant for specifying and reasoning about structure by means of patterns and pattern matching. Its sentences, the patterns, are constructed using variables, symbols, connectives and quantifiers, but no difference is made between function and predicate symbols. In models, a pattern evaluates into a power-set domain (the set of values that match it), in contrast to FOL where functions and predicates map into a regular domain. Matching logic uniformly generalizes several logical frameworks important for program analysis, such as: propositional logic, algebraic specification, FOL with equality, modal logic, and separation logic. Patterns can specify separation requirements at any level in any program configuration, not only in the heaps or stores, without any special logical constructs for that: the very nature of pattern matching is that if two structures are matched as part of a pattern, then they can only be spatially separated. Like FOL, matching logic can also be translated into pure predicate logic with equality, at the same time admitting its own sound and complete proof system. A practical aspect of matching logic is that FOL reasoning with equality remains sound, so off-the-shelf provers and SMT solvers can be used for matching logic reasoning. Matching logic is particularly well-suited for reasoning about programs in programming languages that have an operational semantics, but it is not limited to this

Programming and symbolic computation in Maude

[EN] Rewriting logic is both a flexible semantic framework within which widely different concurrent systems can be naturally specified and a logical framework in which widely different logics can be specified. Maude programs are exactly rewrite theories. Maude has also a formal environment of verification tools. Symbolic computation is a powerful technique for reasoning about the correctness of concurrent systems and for increasing the power of formal tools. We present several new symbolic features of Maude that enhance formal reasoning about Maude programs and the effectiveness of formal tools. They include: (i) very general unification modulo user-definable equational theories, and (ii) symbolic reachability analysis of concurrent systems using narrowing. The paper does not focus just on symbolic features: it also describes several other new Maude features, including: (iii) Maude's strategy language for controlling rewriting, and (iv) external objects that allow flexible interaction of Maude object-based concurrent systems with the external world. In particular, meta-interpreters are external objects encapsulating Maude interpreters that can interact with many other objects. To make the paper self-contained and give a reasonably complete language overview, we also review the basic Maude features for equational rewriting and rewriting with rules, Maude programming of concurrent object systems, and reflection. Furthermore, we include many examples illustrating all the Maude notions and features described in the paper.Duran has been partially supported by MINECO/FEDER project TIN2014-52034-R. Escobar has been partially supported by the EU (FEDER) and the MCIU under grant RTI2018-094403-B-C32, by the Spanish Generalitat Valenciana under grant PROMETE0/2019/098, and by the US Air Force Office of Scientific Research under award number FA9550-17-1-0286. MartiOliet and Rubio have been partially supported by MCIU Spanish project TRACES (TIN2015-67522-C3-3-R). Rubio has also been partially supported by a MCIU grant FPU17/02319. Meseguer and Talcott have been partially supported by NRL Grant N00173 -17-1-G002. Talcott has also been partially supported by ONR Grant N00014-15-1-2202.Durán, F.; Eker, S.; Escobar Román, S.; NARCISO MARTÍ OLIET; José Meseguer; Rubén Rubio; Talcott, C. (2020). Programming and symbolic computation in Maude. Journal of Logical and Algebraic Methods in Programming. 110:1-58. https://doi.org/10.1016/j.jlamp.2019.100497S158110Alpuente, M., Escobar, S., Espert, J., & Meseguer, J. (2014). A modular order-sorted equational generalization algorithm. Information and Computation, 235, 98-136. doi:10.1016/j.ic.2014.01.006K. Bae, J. Meseguer, Predicate abstraction of rewrite theories, in: [36], 2014, pp. 61–76.Bae, K., & Meseguer, J. (2015). Model checking linear temporal logic of rewriting formulas under localized fairness. Science of Computer Programming, 99, 193-234. doi:10.1016/j.scico.2014.02.006Bae, K., Meseguer, J., & Ölveczky, P. C. (2014). Formal patterns for multirate distributed real-time systems. Science of Computer Programming, 91, 3-44. doi:10.1016/j.scico.2013.09.010P. Borovanský, C. Kirchner, H. Kirchner, P.E. Moreau, C. Ringeissen, An overview of ELAN, in: [77], 1998, pp. 55–70.Bouhoula, A., Jouannaud, J.-P., & Meseguer, J. (2000). Specification and proof in membership equational logic. Theoretical Computer Science, 236(1-2), 35-132. doi:10.1016/s0304-3975(99)00206-6Bravenboer, M., Kalleberg, K. T., Vermaas, R., & Visser, E. (2008). Stratego/XT 0.17. A language and toolset for program transformation. Science of Computer Programming, 72(1-2), 52-70. doi:10.1016/j.scico.2007.11.003Bruni, R., & Meseguer, J. (2006). Semantic foundations for generalized rewrite theories. Theoretical Computer Science, 360(1-3), 386-414. doi:10.1016/j.tcs.2006.04.012M. Clavel, F. Durán, S. Eker, S. Escobar, P. Lincoln, N. Martí-Oliet, C.L. Talcott, Two decades of Maude, in: [86], 2015, pp. 232–254.Clavel, M., Durán, F., Eker, S., Lincoln, P., Martı́-Oliet, N., Meseguer, J., & Quesada, J. F. (2002). Maude: specification and programming in rewriting logic. Theoretical Computer Science, 285(2), 187-243. doi:10.1016/s0304-3975(01)00359-0Clavel, M., & Meseguer, J. (2002). Reflection in conditional rewriting logic. Theoretical Computer Science, 285(2), 245-288. doi:10.1016/s0304-3975(01)00360-7F. Durán, S. Eker, S. Escobar, N. Martí-Oliet, J. Meseguer, C.L. Talcott, Associative unification and symbolic reasoning modulo associativity in Maude, in: [121], 2018, pp. 98–114.Durán, F., Lucas, S., Marché, C., Meseguer, J., & Urbain, X. (2008). Proving operational termination of membership equational programs. Higher-Order and Symbolic Computation, 21(1-2), 59-88. doi:10.1007/s10990-008-9028-2F. Durán, J. Meseguer, An extensible module algebra for Maude, in: [77], 1998, pp. 174–195.Durán, F., & Meseguer, J. (2003). Structured theories and institutions. Theoretical Computer Science, 309(1-3), 357-380. doi:10.1016/s0304-3975(03)00312-8Durán, F., & Meseguer, J. (2007). Maude’s module algebra. Science of Computer Programming, 66(2), 125-153. doi:10.1016/j.scico.2006.07.002Durán, F., & Meseguer, J. (2012). On the Church-Rosser and coherence properties of conditional order-sorted rewrite theories. The Journal of Logic and Algebraic Programming, 81(7-8), 816-850. doi:10.1016/j.jlap.2011.12.004F. Durán, P.C. Ölveczky, A guide to extending Full Maude illustrated with the implementation of Real-Time Maude, in: [116], 2009, pp. 83–102.S. Escobar, Multi-paradigm programming in Maude, in: [121], 2018, pp. 26–44.Escobar, S., Meadows, C., Meseguer, J., & Santiago, S. (2014). State space reduction in the Maude-NRL Protocol Analyzer. Information and Computation, 238, 157-186. doi:10.1016/j.ic.2014.07.007Escobar, S., Sasse, R., & Meseguer, J. (2012). Folding variant narrowing and optimal variant termination. The Journal of Logic and Algebraic Programming, 81(7-8), 898-928. doi:10.1016/j.jlap.2012.01.002H. Garavel, M. Tabikh, I. Arrada, Benchmarking implementations of term rewriting and pattern matching in algebraic, functional, and object-oriented languages – the 4th rewrite engines competition, in: [121], 2018, pp. 1–25.Goguen, J. A., & Burstall, R. M. (1992). Institutions: abstract model theory for specification and programming. Journal of the ACM, 39(1), 95-146. doi:10.1145/147508.147524Goguen, J. A., & Meseguer, J. (1984). Equality, types, modules, and (why not?) generics for logic programming. The Journal of Logic Programming, 1(2), 179-210. doi:10.1016/0743-1066(84)90004-9Goguen, J. A., & Meseguer, J. (1992). Order-sorted algebra I: equational deduction for multiple inheritance, overloading, exceptions and partial operations. Theoretical Computer Science, 105(2), 217-273. doi:10.1016/0304-3975(92)90302-vR. Gutiérrez, J. Meseguer, Variant-based decidable satisfiability in initial algebras with predicates, in: [61], 2018, pp. 306–322.Gutiérrez, R., Meseguer, J., & Rocha, C. (2015). Order-sorted equality enrichments modulo axioms. Science of Computer Programming, 99, 235-261. doi:10.1016/j.scico.2014.07.003Horn, A. (1951). On sentences which are true of direct unions of algebras. Journal of Symbolic Logic, 16(1), 14-21. doi:10.2307/2268661Katelman, M., Keller, S., & Meseguer, J. (2012). Rewriting semantics of production rule sets. The Journal of Logic and Algebraic Programming, 81(7-8), 929-956. doi:10.1016/j.jlap.2012.06.002Kowalski, R. (1979). Algorithm = logic + control. Communications of the ACM, 22(7), 424-436. doi:10.1145/359131.359136Lucanu, D., Rusu, V., & Arusoaie, A. (2017). A generic framework for symbolic execution: A coinductive approach. Journal of Symbolic Computation, 80, 125-163. doi:10.1016/j.jsc.2016.07.012D. Lucanu, V. Rusu, A. Arusoaie, D. Nowak, Verifying reachability-logic properties on rewriting-logic specifications, in: [86], 2015, pp. 451–474.Lucas, S., & Meseguer, J. (2016). Normal forms and normal theories in conditional rewriting. Journal of Logical and Algebraic Methods in Programming, 85(1), 67-97. doi:10.1016/j.jlamp.2015.06.001N. Martí-Oliet, J. Meseguer, A. Verdejo, A rewriting semantics for Maude strategies, in: [116], 2009, pp. 227–247.Martí-Oliet, N., Palomino, M., & Verdejo, A. (2007). Strategies and simulations in a semantic framework. Journal of Algorithms, 62(3-4), 95-116. doi:10.1016/j.jalgor.2007.04.002Meseguer, J. (1992). Conditional rewriting logic as a unified model of concurrency. Theoretical Computer Science, 96(1), 73-155. doi:10.1016/0304-3975(92)90182-fMeseguer, J. (2012). Twenty years of rewriting logic. The Journal of Logic and Algebraic Programming, 81(7-8), 721-781. doi:10.1016/j.jlap.2012.06.003Meseguer, J. (2017). Strict coherence of conditional rewriting modulo axioms. Theoretical Computer Science, 672, 1-35. doi:10.1016/j.tcs.2016.12.026J. Meseguer, Generalized rewrite theories and coherence completion, in: [121], 2018, pp. 164–183.Meseguer, J. (2018). Variant-based satisfiability in initial algebras. Science of Computer Programming, 154, 3-41. doi:10.1016/j.scico.2017.09.001Meseguer, J., Goguen, J. A., & Smolka, G. (1989). Order-sorted unification. Journal of Symbolic Computation, 8(4), 383-413. doi:10.1016/s0747-7171(89)80036-7Meseguer, J., & Ölveczky, P. C. (2012). Formalization and correctness of the PALS architectural pattern for distributed real-time systems. Theoretical Computer Science, 451, 1-37. doi:10.1016/j.tcs.2012.05.040Meseguer, J., Palomino, M., & Martí-Oliet, N. (2008). Equational abstractions. Theoretical Computer Science, 403(2-3), 239-264. doi:10.1016/j.tcs.2008.04.040Meseguer, J., & Roşu, G. (2007). The rewriting logic semantics project. Theoretical Computer Science, 373(3), 213-237. doi:10.1016/j.tcs.2006.12.018Meseguer, J., & Roşu, G. (2013). The rewriting logic semantics project: A progress report. Information and Computation, 231, 38-69. doi:10.1016/j.ic.2013.08.004Meseguer, J., & Skeirik, S. (2017). Equational formulas and pattern operations in initial order-sorted algebras. Formal Aspects of Computing, 29(3), 423-452. doi:10.1007/s00165-017-0415-5Meseguer, J., & Thati, P. (2007). Symbolic reachability analysis using narrowing and its application to verification of cryptographic protocols. Higher-Order and Symbolic Computation, 20(1-2), 123-160. doi:10.1007/s10990-007-9000-6C. Olarte, E. Pimentel, C. Rocha, Proving structural properties of sequent systems in rewriting logic, in: [121], 2018, pp. 115–135.Ölveczky, P. C., & Meseguer, J. (2007). Semantics and pragmatics of Real-Time Maude. Higher-Order and Symbolic Computation, 20(1-2), 161-196. doi:10.1007/s10990-007-9001-5Ölveczky, P. C., & Thorvaldsen, S. (2009). Formal modeling, performance estimation, and model checking of wireless sensor network algorithms in Real-Time Maude. Theoretical Computer Science, 410(2-3), 254-280. doi:10.1016/j.tcs.2008.09.022Rocha, C., Meseguer, J., & Muñoz, C. (2017). Rewriting modulo SMT and open system analysis. Journal of Logical and Algebraic Methods in Programming, 86(1), 269-297. doi:10.1016/j.jlamp.2016.10.001Şerbănuţă, T. F., Roşu, G., & Meseguer, J. (2009). A rewriting logic approach to operational semantics. Information and Computation, 207(2), 305-340. doi:10.1016/j.ic.2008.03.026Skeirik, S., & Meseguer, J. (2018). Metalevel algorithms for variant satisfiability. Journal of Logical and Algebraic Methods in Programming, 96, 81-110. doi:10.1016/j.jlamp.2017.12.006S. Skeirik, A. Ştefănescu, J. Meseguer, A constructor-based reachability logic for rewrite theories, in: [61], 2018, pp. 201–217.Strachey, C. (2000). Higher-Order and Symbolic Computation, 13(1/2), 11-49. doi:10.1023/a:1010000313106A. Ştefănescu, S. Ciobâcă, R. Mereuta, B.M. Moore, T. Serbanuta, G. Roşu, All-path reachability logic, in: [36], 2014, pp. 425–440.Tushkanova, E., Giorgetti, A., Ringeissen, C., & Kouchnarenko, O. (2015). A rule-based system for automatic decidability and combinability. Science of Computer Programming, 99, 3-23. doi:10.1016/j.scico.2014.02.00