scholarly journals Using Vampire with Support for Algebraic Datatypes in Type Soundness Proofs

10.29007/pmmz ◽  
2018 ◽  
Author(s):  
Sylvia Grewe ◽  
André Pacak ◽  
Mira Mezini
Keyword(s):  
Type System ◽  
Type Systems ◽  
First Order ◽  
Domain Specific ◽  
The Past ◽  
Finite Term ◽  
The Individual ◽  
Input Format ◽  
Ongoing Project ◽  
Superposition Calculus

In our ongoing project VeriTaS, we aim at automating soundness proofs for type sys- tems of domain-specific languages. In the past, we successfully used previous Vampire versions for automatically discharging many intermediate proof obligations arising within standard soundness proofs for small type systems. With older Vampire versions, encoding the individual proof problems required manual encoding of algebraic datatypes via the theory of finite term algebras. One of the new Vampire versions now supports the direct specification of algebraic datatypes and integrates reasoning about term algebras into the internally used superposition calculus.In this work, we investigate how many proof problems that typically arise within type soundness proofs different Vampire 4.1 versions can prove. Our test set consists of proof problems from a progress proof of a type system for a subset of SQL. We compare running Vampire 4.1 with our own encodings of algebraic datatypes (in untyped as well as in typed first-order logic) to running Vampire 4.1 with support for algebraic datatypes, which uses SMTLIB as input format. We observe that with our own encodings, Vampire 4.1 still proves more of our input problems. We discuss the differences between our own encoding of algebraic datatypes and the ones used within Vampire 4.1 with support for algebraic datatypes.

scholarly journals Using Vampire in Soundness Proofs of Type Systems

10.29007/22x6 ◽  
2018 ◽  
Author(s):  
Sylvia Grewe ◽  
Sebastian Erdweg ◽  
Mira Mezini
Keyword(s):  
Programming Languages ◽  
Type System ◽  
Lambda Calculus ◽  
Type Systems ◽  
Current Approach ◽  
Order Logic ◽  
First Order Logic ◽  
First Order ◽  
Domain Specific ◽  
Automated Proof

Type systems for programming languages shall detect type errors in programs before runtime. To ensure that a type system meets this requirement, its soundness must be formally verified. We aim at automating soundness proofs of type systems to facilitate the development of sound type systems for domain-specific languages.Soundness proofs for type systems typically require induction. However, many of the proofs of individual induction cases only require first-order reasoning. For the development of our workbench Veritas, we build on this observation by combining automated first-order theorem provers such as Vampire with automated proof strategies specific to type systems. In this paper, we describe how we encode type soundness proofs in first-order logic using TPTP. We show how we use Vampire to prove the soundness of type systems for the simply-typed lambda calculus and for parts of a typed SQL. We report on which parts of the proofs are handled well by Vampire, and what parts work less well with our current approach.

Exploring the Dimensions of Recovery and User Experience

2014 ◽  
Vol 3 (4) ◽  
pp. 305-311
Author(s):  
Peter Jones
Keyword(s):  
Mental Health ◽  
Mental Health Service ◽  
Health Service ◽  
Health Service Provision ◽  
Domain Specific ◽  
The Past ◽  
Economic Climate ◽  
Health And Social Care ◽  
The Individual ◽  
Mental Health Service Provision

The concept of recovery is widely applied within service delivery in the field of mental health. The dimensions of recovery were explored using a singular conceptual framework known as Hodges’ model, which is shown to be suited to this particular task. This arises from the model’s structure, in that it encompasses the individual-group and a care domain specific to the political aspects of both health and social care. The evidence was found by relating recovery to the model’s care domains, which is also relevant to the experience of mental health service users and developments over the past decade in mental health service provision. Particular attention is given to the ‘Recovery Star’. This can be used as a key-working and outcomes tool. The discussion is also placed in a context of the current socio-economic climate, notably the ‘politics of recovery’ at a time of austerity.

scholarly journals Automating Proof Steps of Progress Proofs: Comparing Vampire and Dafny

10.29007/5zjp ◽  
2018 ◽  
Author(s):  
Sylvia Grewe ◽  
Sebastian Erdweg ◽  
Mira Mezini
Keyword(s):  
Formal Methods ◽  
Programming Language ◽  
Type System ◽  
Type Systems ◽  
Domain Specific Languages ◽  
Smt Solver ◽  
Domain Specific ◽  
Efficient Type

\noindent Developing provably sound type systems is a non-trivial task which, as of today, typically requires expert skills in formal methods and a considerable amount of time. Our Veritas~\cite{GreweErdwegWittmannMezini15} project aims at providing support for the development of soundness proofs of type systems and efficient type checker implementations from specifications of type systems. To this end, we investigate how to best automate typical steps within type soundness proofs.\noindent In this paper, we focus on progress proofs for type systems of domain-specific languages. As a running example for such a type system, we model a subset SQL and augment it with a type system. We compare two different approaches for automating proof steps of the progress proofs for this type system against each other: firstly, our own tool Veritas, which translates proof goals and specifications automatically to TPTP~\cite{Sutcliffe98} and calls Vampire~\cite{KovacsV13} on them, and secondly, the programming language Dafny~\cite{Leino2010}, which translates proof goals and specifications to the intermediate verification language Boogie 2~\cite{Leino2008} and calls the SMT solver Z3~\cite{DeMoura2008} on them. We find that Vampire and Dafny are equally well-suited for automatically proving simple steps within progress proofs.

Phantom types and subtyping

2006 ◽  
Vol 16 (6) ◽  
pp. 751-791 ◽  
Author(s):  
MATTHEW FLUET ◽  
RICCARDO PUCELLA
Keyword(s):  
Type System ◽  
Type Systems ◽  
First Order ◽  
Standard Ml ◽  
Parametric Polymorphism ◽  
The One ◽  
Multiple Interface

We investigate a technique from the literature, called the phantom-types technique, that uses parametric polymorphism, type constraints, and unification of polymorphic types to model a subtyping hierarchy. Hindley-Milner type systems, such as the one found in Standard ML, can be used to enforce the subtyping relation, at least for first-order values. We show that this technique can be used to encode any finite subtyping hierarchy (including hierarchies arising from multiple interface inheritance). We formally demonstrate the suitability of the phantom-types technique for capturing first-order subtyping by exhibiting a type-preserving translation from a simple calculus with bounded polymorphism to a calculus embodying the type system of SML.

ON THE CONSERVATIVITY OF LEIBNIZ EQUALITY

1998 ◽  
Vol 09 (04) ◽  
pp. 431-454
Author(s):  
M. P. A. SELLINK
Keyword(s):  
Type System ◽  
Type Systems ◽  
Order Theory ◽  
Second Order ◽  
First Order ◽  
Pure Type ◽  
First Order Theory ◽  
Pure Type Systems ◽  
Leibniz Equality

We embed a first order theory with equality in the Pure Type System λMON2 that is a subsystem of the well-known type system λPRED2. The embedding is based on the Curry-Howard isomorphism, i.e. → and ∀ coincide with → and Π. Formulas of the form [Formula: see text] are treated as Leibniz equalities. That is, [Formula: see text] is identified with the second order formula ∀ P. P(t1)→ P(t2), which contains only →'s and ∀'s and can hence be embedded straightforwardly. We give a syntactic proof — based on enriching typed λ-calculus with extra reduction steps — for the equivalence between derivability in the logic and inhabitance in λMNO2. Familiarity with Pure Type Systems is assumed.

scholarly journals Type errors for the IDE with Xtext and Xsemantics

2019 ◽  
Vol 9 (1) ◽  
pp. 52-79
Author(s):  
Lorenzo Bettini
Keyword(s):  
Type System ◽  
Type Systems ◽  
Error Recovery ◽  
Simple Expression ◽  
Type Inference ◽  
Domain Specific Language ◽  
Immediate Feedback ◽  
Domain Specific ◽  
Formal Systems ◽  
Efficient Type

AbstractProviding IDE support for a programming language or a DSL (Domain Specific Language) helps the users of the language to be more productive and to have an immediate feedback on possible errors in a program. Static types can drive IDE mechanisms such as the content assist to propose sensible completions in a given program context. Types can also be used to enrich other typical IDE parts such as the Outline and theHovering pop-ups. In this paper, we focus on statically typed imperative languages, adopting some form of type inference. We present a few general patterns for implementing efficient type systems, focusing on type error recovery. This way, the type system is able to type as many parts of the program as possible, keeping a good IDE experience. Type error messages will be placed on the important parts of the program, avoiding cascading errors that can confuse the user. We show two case studies:we apply the presented patterns to implement the type system of two statically typed DSLs, a simple expression language and a reduced Java-like language, with OOP features. We use Xtext as the language workbench for implementing the compiler and the IDE support andXsemantics, a DSL for implementing type systems using a syntax that mimics formal systems. The patterns shown in the paper can be reused also for implementing languages with other language frameworks.

Five Years and Count(er)ing: Memoir after Memoir

CounterText ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 26-32
Author(s):  
Norbert Bugeja
Keyword(s):  
Guest Editor ◽  
Arab Countries ◽  
National Museum ◽  
Terror Attack ◽  
Special Issue ◽  
The Past ◽  
Personal Perspectives ◽  
The Moment ◽  
Ongoing Project

In this retrospective piece, the Guest Editor of the first number of CounterText (a special issue titled Postcolonial Springs) looks back at the past five years from various scholarly and personal perspectives. He places particular focus on an event that took place mid-way between the 2011 uprisings across a number of Arab countries and the moment of writing: the March 2015 terror attack on the Bardo National Museum in Tunis, which killed twenty-two people and had a profound effect on Tunisian popular consciousness and that of the post-2011 Arab nations. In this context, the author argues for a renewed perspective on memoir as at once a memorial practice and a political gesture in writing, one that exceeds concerns of genre and form to encompass an ongoing project of political re-cognition following events that continue to remap the agenda for the region. The piece makes a brief final pitch for Europe's need to re-cognise, within those modes of ‘articulacy-in-difficulty’ active on its southern borders, specific answers to its own present quandaries.

POLITICAL IDEOLOGY AS AN EVOLUTIONARY SYSTEM (TO THE THEORY OF COGNITIVE-IDEOLOGICAL MATRICES)

2020 ◽  
Author(s):  
Mikhail Konstantinov
Keyword(s):  
Political Ideology ◽  
Evolutionary System ◽  
Consciousness Level ◽  
The Past ◽  
Political Ideologies ◽  
Morphological Approach ◽  
Main Gene ◽  
Individual Consciousness ◽  
The Individual ◽  
Sociological Studies

The aim of the article is to concretize the concept of political ideology in the aspect of its matrix structure and in the context of the cognitive-evolutionary approach. Based on Michael Frieden's morphological approach to the analysis of ideological consciousness, the concept of cognitive-ideological matrices is introduced, which allows us to describe the process of transition from proto-ideological to ideological concepts proper, especially at the level of individual consciousness. The identification of the ideological concept as the main “gene” of conceptual variability and inheritance made it possible to describe the main parameters of the evolution of political ideologies and associate it with changes taking place at the individual consciousness level. The described concept was tested in a series of sociological studies of youth consciousness conducted in 2015-2016 and 2018-2020. As a result of the study, it was possible to first identify the “zero level” of ideology, at which the minds of young respondents are potentially open to the influence of diverse and often mutually exclusive ideological orientations, and second, to pinpoint the changes that have occurred in the cognitive ideological matrices of Rostov-on-Don students over the past five years. This study was conducted by scientists from the southern Federal University.

Anti-Inflammatory Properties of Plant Derived Natural Products – A Systematic Review

2019 ◽  
Vol 26 (24) ◽  
pp. 4506-4536 ◽  
Author(s):  
Iris E. Allijn ◽  
René P. Brinkhuis ◽  
Gert Storm ◽  
Raymond M. Schiffelers
Keyword(s):  
Systematic Review ◽  
Natural Products ◽  
Positive Control ◽  
Therapeutic Effects ◽  
Reference Compound ◽  
Individual Molecular Species ◽  
The Past ◽  
Anti Inflammatory ◽  
The Individual ◽  
Natural Medicines

Traditionally, natural medicines have been administered as plant extracts, which are composed of a mixture of molecules. The individual molecular species in this mixture may or may not contribute to the overall medicinal effects and some may even oppose the beneficial activity of others. To better control therapeutic effects, studies that characterized specific molecules and describe their individual activity that have been performed over the past decades. These studies appear to underline that natural products are particularly effective as antioxidants and anti-inflammatory agents. In this systematic review we aimed to identify potent anti-inflammatory natural products and relate their efficacy to their chemical structure and physicochemical properties. To identify these compounds, we performed a comprehensive literature search to find those studies, in which a dose-response description and a positive control reference compound was used to benchmark the observed activity. Of the analyzed papers, 7% of initially selected studies met these requirements and were subjected to further analysis. This analysis revealed that most selected natural products indeed appeared to possess anti-inflammatory activities, in particular anti-oxidative properties. In addition, 14% of the natural products outperformed the remaining natural products in all tested assays and are attractive candidates as new anti-inflammatory agents.

Temporal Focus

2020 ◽  
Author(s):  
Abbie J. Shipp
Keyword(s):  
Well Being ◽  
Psychology Research ◽  
The Past ◽  
Research Areas ◽  
The Future ◽  
Behavior Based ◽  
The Individual ◽  
And Behavior ◽  
Temporal Focus

Temporal focus is the individual tendency to characteristically think more or less about the past, present, and future. Although originally rooted in early work from psychology, research on temporal focus has been steadily growing in a number of research areas, particularly since Zimbardo and Boyd’s (1999) influential article on the topic. This chapter will review temporal focus research from the past to the present, including how temporal focus has been conceptualized and measured, and which correlates and outcomes have been tested in terms of well-being and behavior. Based on this review, an agenda for research is created to direct temporal focus research in the future.

Sign in / Sign up

Export Citation Format

Share Document