Polymorphic set-theoretic types for functional languages

We study set-theoretic types: types that include union, intersection, and negation connectives. Set-theoretic types, coupled with a suitable subtyping relation, are useful to type several programming language constructs \u2013 including conditional branching, pattern matching, and function overloading \u2013 very precisely. We define subtyping following the semantic subtyping approach, which interprets types as sets and defines subtyping as set inclusion. Our set-theoretic types are polymorphic, that is, they contain type variables to allow parametric polymorphism. We extend previous work on set-theoretic types and semantic subtyping by showing how to adapt them to new settings and apply them to type various features of functional languages. More precisely, we integrate semantic subtyping with three important language features. In Part I we study implicitly typed languages with let-polymorphism and type inference (previous work on semantic subtyping focused on explicitly typed languages). We describe an implicitly typed lambda-calculus and a declarative type system for which we prove soundness. We study type inference and prove results of soundness and completeness. Then, we show how to make type inference more precise when programs are partially annotated with types. In Part II we study gradual typing. We describe a new approach to add gradual typing to a static type system; the novelty is that we give a declarative presentation of the type system, while previous work considered algorithmic presentations. We first illustrate the approach on a Hindley-Milner type system without subtyping. We describe declarative typing, compilation to a cast language, and sound and complete type inference. Then, we add set-theoretic types, defining a subtyping relation on set-theoretic gradual types, and we describe sound type inference for the extended system. In Part III we consider non-strict semantics. The existing semantic subtyping systems are designed for call-by-value languages and are unsound for non-strict semantics. We adapt them to obtain soundness for call-by-need. To do so, we introduce an explicit representation for divergence in the types, allowing the type system to distinguish the expressions that are already evaluated from those that are computations which might diverge.Cette th\ue8se porte sur l'\ue9tude des types ensemblistes : des types qui contiennent des connecteurs d'union, d'intersection et de n\ue9gation. Les types ensemblistes permettent de typer de mani\ue8re tr\ue8s pr\ue9cise plusieurs constructions des langages de programmation (comme par exemple les branches conditionnelles, le filtrage par motif et la surcharge des fonctions) lorsqu'ils sont utilis\ue9s avec une notion appropri\ue9e de sous-typage. Pour d\ue9finir celle-ci, nous utilisons l'approche du sous-typage s\ue9mantique, dans laquelle les types sont interpr\ue9t\ue9s comme des ensembles, et o\uf9 le sous-typage est d\ue9fini comme l'inclusion ensembliste. Dans la plupart de cette th\ue8se, les types ensemblistes sont polymorphes, dans le sens o\uf9 ils contiennent des variables de type pour permettre le polymorphisme param\ue9trique. La th\ue8se \ue9tend les travaux pr\ue9c\ue9dents sur les types ensemblistes et le sous-typage s\ue9mantique en montrant comment les adapter \ue0 des nouveaux contextes et comment les utiliser pour typer plusieurs aspects des langages fonctionnels. Elle se compose de trois parties. La premi\ue8re partie porte sur une \ue9tude des langages typ\ue9s de mani\ue8re implicite avec polymorphisme du "let" et inf\ue9rence de types (contrairement aux travaux pr\ue9c\ue9dents sur le sous-typage s\ue9mantique qui \ue9tudiaient des langages typ\ue9s explicitement). Nous y d\ue9crivons un lambda-calcul typ\ue9 implicitement avec un syst\ue8me de types dont nous d\ue9montrons la correction. De m\ueame, nous y \ue9tudions l'inf\ue9rence de types dont nous d\ue9montrons la correction et la compl\ue9tude. Enfin, nous montrons comment rendre l'inf\ue9rence plus pr\ue9cise quand les programmes sont partiellement annot\ue9s avec des types. La deuxi\ue8me partie d\ue9crit une nouvelle approche permettant d'\ue9tendre un syst\ue8me de types statique avec du typage graduel; l'originalit\ue9 venant du fait que nous d\ue9crivons le syst\ue8me de types de fa\ue7on d\ue9clarative, lorsque les syst\ue8mes existants proposent des descriptions algorithmiques. Nous illustrons cette approche en ajoutant le typage graduel \ue0 un syst\ue8me de types \ue0 la Hindley-Milner sans sous-typage. Nous d\ue9crivons pour cela un syst\ue8me de types d\ue9claratif, un processus de compilation vers un langage avec v\ue9rifications de type dynamiques (ou "casts"), et nous pr\ue9sentons un syst\ue8me d'inf\ue9rence de types correct et complet. Ensuite, nous y ajoutons les types ensemblistes, en d\ue9finissant une relation de sous-typage sur les types graduel ensemblistes, puis en pr\ue9sentant un syst\ue8me d'inf\ue9rence de types correct pour le syst\ue8me \ue9tendu. La troisi\ue8me partie porte sur l'\ue9tude des s\ue9mantiques non-strictes. Les syst\ue8mes existants qui utilisent le sous-typage s\ue9mantique ont \ue9t\ue9 d\ue9velopp\ue9s pour des langages avec appel par valeur et ne sont pas s\ufbrs pour des s\ue9mantiques non-strictes. Nous montrons ici comment les adapter pour garantir leur s\ufbret\ue9 en appel par n\ue9cessit\ue9. Pour faire \ue7a, nous introduisons dans les types une repr\ue9sentation explicite de la divergence, afin que le syst\ue8me des types puisse distinguer les expressions qui ne demandent pas d'\ue9valuation de celles qui la demandent et pourraient ainsi diverger

Semantic Subtyping for Non-Strict Languages

Semantic subtyping is an approach to define subtyping relations for type systems featuring union and intersection type connectives. It has been studied only for strict languages, and it is unsound for non-strict semantics. In this work, we study how to adapt this approach to non-strict languages: in particular, we define a type system using semantic subtyping for a functional language with a call-by-need semantics. We do so by introducing an explicit representation for divergence in the types, so that the type system distinguishes expressions that are results from those which are computations that might diverge

Set-Theoretic Types for Polymorphic Variants

Polymorphic variants are a useful feature of the OCaml language whose current definition and implementation rely on kinding constraints to simulate a subtyping relation via unification. This yields an awkward formalization and results in a type system whose behaviour is in some cases unintuitive and/or unduly restrictive. In this work, we present an alternative formalization of poly-morphic variants, based on set-theoretic types and subtyping, that yields a cleaner and more streamlined system. Our formalization is more expressive than the current one (it types more programs while preserving type safety), it can internalize some meta-theoretic properties, and it removes some pathological cases of the current implementation resulting in a more intuitive and, thus, predictable type system. More generally, this work shows how to add full-fledged union types to functional languages of the ML family that usually rely on the Hindley-Milner type system. As an aside, our system also improves the theory of semantic subtyping, notably by proving completeness for the type reconstruction algorithm.Comment: ACM SIGPLAN International Conference on Functional Programming, Sep 2016, Nara, Japan. ICFP 16, 21st ACM SIGPLAN International Conference on Functional Programming, 201

Multimode Trapped Interferometer with Ideal Bose-Einstein Condensates

We experimentally demonstrate a multi-mode interferometer comprising a Bose-Einstein condensate of $^{39}$K atoms trapped in a harmonic potential, where the interatomic interaction can be cancelled exploiting Feshbach resonances. Kapitza-Dirac diffraction from an optical lattice coherently splits the BEC in multiple momentum components equally spaced that form different interferometric paths, closed by the trapping harmonic potential. We investigate two different interferometric schemes, where the recombination pulse is applied after a full or half oscillation in the confining potential. We find that the relative amplitudes of the momentum components at the interferometer output are sensitive to external forces, through the induced displacement of the harmonic potential with respect to the optical lattice. We show how to calibrate the interferometer, fully characterize its output and discuss perspective improvements.Comment: 7 pages, 6 figure

Per il centenario di Angela Vinay: impegno civile, costruzione e attualità dei servizi bibliotecari nazionali (Roma, Biblioteca nazionale centrale, 24 novembre 2022)

Angela Vinay (1922-1990) was a leading personality in the history of Italian libraries of the twentieth century. Among the numerous and prestigious positions she held, she was the first female president of the Italian Library Association as well as the director of the Central Institute for the Union Catalogue (ICCU), where she conceived and promoted the National Library Service (SBN). This dossier collects the papers of the conference “For Angela Vinay’s centenary: civil commitment, construction and modernity of nationwide library services”, held in her honour at the Central National Library of Rome on the 24th of November 2022.Angela Vinay (1922-1990) è stata un’importante protagonista della storia delle biblioteche italiane del Novecento. Tra i numerosi e prestigiosi incarichi ricoperti è stata la prima donna presidente dell’Associazione italiana biblioteche nonché direttrice dell’Istituto centrale per il catalogo unico (ICCU) dove ideò e promosse il Servizio bibliotecario nazionale (SBN). Il presente dossier raccoglie le relazioni del convegno in suo onore “Per il centenario di Angela Vinay: impegno civile, costruzione e attualità dei servizi bibliotecari nazionali”, svoltosi presso la Biblioteca nazionale centrale di Roma il 24 novembre 2022

Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI

Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

Search for stop and higgsino production using diphoton Higgs boson decays

Results are presented of a search for a "natural" supersymmetry scenario with gauge mediated symmetry breaking. It is assumed that only the supersymmetric partners of the top-quark (stop) and the Higgs boson (higgsino) are accessible. Events are examined in which there are two photons forming a Higgs boson candidate, and at least two b-quark jets. In 19.7 inverse femtobarns of proton-proton collision data at sqrt(s) = 8 TeV, recorded in the CMS experiment, no evidence of a signal is found and lower limits at the 95% confidence level are set, excluding the stop mass below 360 to 410 GeV, depending on the higgsino mass