TRX: A Formally Verified Parser Interpreter

Parsing is an important problem in computer science and yet surprisingly little attention has been devoted to its formal verification. In this paper, we present TRX: a parser interpreter formally developed in the proof assistant Coq, capable of producing formally correct parsers. We are using parsing expression grammars (PEGs), a formalism essentially representing recursive descent parsing, which we consider an attractive alternative to context-free grammars (CFGs). From this formalization we can extract a parser for an arbitrary PEG grammar with the warranty of total correctness, i.e., the resulting parser is terminating and correct with respect to its grammar and the semantics of PEGs; both properties formally proven in Coq.Comment: 26 pages, LMC

A Mechanized Proof of a Textbook Type Unification Algorithm

Unification is the core of type inference algorithms for modern functional programming languages, like Haskell and SML. As a first step towards a formalization of a type inference algorithm for such programming languages, we present a formalization in Coq of a type unification algorithm that follows classic algorithms presented in programming language textbooks. We also report on the use of such formalization to build a correct type inference algorithm for the simply typed λ-calculus

A type-checking preprocessor for Cilk 2, a multithreaded C language

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1995.Includes bibliographical references (p. 37-38).by Robert C. Miller.M.Eng

Clinician empathic speech and client change language : is there an association between empathic speech and change talk in motivational interviewing sessions?

Empathy is the state of knowing or being aware of another persons perspective and the ability to express empathy is acknowledged as an important component within effective psychotherapy. Motivational interviewing (MI) is a specific method of psychotherapy in which clinician expressions of empathy are held to be an active ingredient and a central component of effective practice. Although empathy has long been a part of the theoretical explanation of effective MI, there is little known about the function of empathy as expressed by the clinician and the association between such in-session speech and client change language. This study identified the empathic speech of clinicians and explored the association of such speech with client change language. The study found that frequencies of empathic speech shared a significant positive correlation with client change talk as well as client sustain talk. This correlation between empathic speech and change talk was mediated by several clinician variables, such as MI-consistent behaviors and clinician reflections of client change talk. Similarly, the relationship between empathic speech and client sustain talk was mediated by reflections of client sustain talk

Meta-F*: Proof Automation with SMT, Tactics, and Metaprograms

We introduce Meta-F*, a tactics and metaprogramming framework for the F* program verifier. The main novelty of Meta-F* is allowing the use of tactics and metaprogramming to discharge assertions not solvable by SMT, or to just simplify them into well-behaved SMT fragments. Plus, Meta-F* can be used to generate verified code automatically. Meta-F* is implemented as an F* effect, which, given the powerful effect system of F*, heavily increases code reuse and even enables the lightweight verification of metaprograms. Metaprograms can be either interpreted, or compiled to efficient native code that can be dynamically loaded into the F* type-checker and can interoperate with interpreted code. Evaluation on realistic case studies shows that Meta-F* provides substantial gains in proof development, efficiency, and robustness.Comment: Full version of ESOP'19 pape

Extensible Markup Language (XML) 1.1

El lenguaje extensible de marcas (XML) es un subconjunto de SGML, y aparece completamente definido en este documento. Su objetivo es permitir que SGML genérico pueda ser servido, recibido y procesado en la Web en la misma manera que hoy es posible con HTML. XML ha sido diseñado de tal manera que sea fácil de implementar y buscando interoperabilidad tanto con SGML como con HTML.Second editio

Deep into Pharo

International audienceThis is a book on Pharo a programming language available at http://www.pharo.or

Proceedings of the International Collaborative Effort on Automating Mortality Statistics, Volume II

Arialdi M. Minino and Harry M. Rosenberg, editors."September 2001.""Second plenary meeting of the International Collaborative Effort on Automating Mortality Statistics held in Bethesda, Maryland, September 7-10, 1999"--Pref.Sponsored by the Centers for Disease Control and Prevention, National Center for Health Statistics.Also available via the World Wide Web.Includes bibliographical references