scholarly journals A Prolog-based Proof Tool for Type-Theory TA-lambda and Implicational Intuitionistic-Logic

10.29007/8ttk ◽  
2018 ◽  
Author(s):  
L. Yohanes Stefanus ◽  
Ario Santoso
Keyword(s):  
Normal Form ◽  
Computer Science ◽  
Intuitionistic Logic ◽  
Type Theory ◽  
General Type ◽  
Search Algorithm ◽  
Principal Type ◽  
Web Based ◽  
Type Algorithm ◽  
Important Variant

Studies on type theory have brought numerous important contributions to computer science. In this paper we present a GUI-based proof tool that provides assistance in constructing deductions in type theory and validating implicational intuitionistic logic formulas. As such, this proof tool is a testbed for learning type theory and implicational intuitionistic logic. This proof tool focuses on an important variant of type theory named TA<sub>λ</sub>, especially on its two core algorithms: the principal-type algorithm and the type inhabitant search algorithm. The former algorithm finds a most general type assignable to a given λ-term, while the latter finds inhabitants (closed λ-terms in β-normal form) to which a given type can be assigned. By the Curry-Howard correspondence, the latter algorithm provides provability for implicational formulas in intuitionistic logic. We elaborate on how to implement those two algorithms declaratively in Prolog and the overall GUI-based program architecture. In our implementation, we make some modification to improve the performance of the principal-type algorithm. We have also built a web-based version of the proof tool called λ-Guru.

scholarly journals Quotienting the delay monad by weak bisimilarity

2017 ◽  
Vol 29 (1) ◽  
pp. 67-92 ◽  
Author(s):  
JAMES CHAPMAN ◽  
TARMO UUSTALU ◽  
NICCOLÒ VELTRI
Keyword(s):  
Computer Science ◽  
Equivalence Relation ◽  
Type Theory ◽  
Partial Functions ◽  
Homotopy Type Theory ◽  
Inductive Type ◽  
Alternative Approach ◽  
The One ◽  
Axiom Of Countable Choice

The delay datatype was introduced by Capretta (Logical Methods in Computer Science, 1(2), article 1, 2005) as a means to deal with partial functions (as in computability theory) in Martin-Löf type theory. The delay datatype is a monad. It is often desirable to consider two delayed computations equal, if they terminate with equal values, whenever one of them terminates. The equivalence relation underlying this identification is called weak bisimilarity. In type theory, one commonly replaces quotients with setoids. In this approach, the delay datatype quotiented by weak bisimilarity is still a monad–a constructive alternative to the maybe monad. In this paper, we consider the alternative approach of Hofmann (Extensional Constructs in Intensional Type Theory, Springer, London, 1997) of extending type theory with inductive-like quotient types. In this setting, it is difficult to define the intended monad multiplication for the quotiented datatype. We give a solution where we postulate some principles, crucially proposition extensionality and the (semi-classical) axiom of countable choice. With the aid of these principles, we also prove that the quotiented delay datatype delivers free ω-complete pointed partial orders (ωcppos).Altenkirch et al. (Lecture Notes in Computer Science, vol. 10203, Springer, Heidelberg, 534–549, 2017) demonstrated that, in homotopy type theory, a certain higher inductive–inductive type is the free ωcppo on a type X essentially by definition; this allowed them to obtain a monad of free ωcppos without recourse to a choice principle. We notice that, by a similar construction, a simpler ordinary higher inductive type gives the free countably complete join semilattice on the unit type 1. This type suffices for constructing a monad, which is isomorphic to the one of Altenkirch et al. We have fully formalized our results in the Agda dependently typed programming language.

A web-based language learning environment: general architecture

ReCALL ◽  
1999 ◽  
Vol 11 (S1) ◽  
pp. 31-39
Author(s):  
Pierre-Yves Foucou ◽  
Natalie Kübler
Keyword(s):  
Learning Environment ◽  
Language Learning ◽  
Computer Science ◽  
Subject Area ◽  
Point Of View ◽  
Learning Activities ◽  
Web Based ◽  
Wide Range ◽  
General Architecture ◽  
The Web

In this paper, we present the Web-based CALL environment (or WALL) which is currently being experimented with at the University of Paris 13 in the Computer Science Department of the Institut Universitaire de Technologie. Our environment is being developed to teach computer science (CS) English to CS French-speaking students, and will be extended to other languages for specific purposes such as, for example, English or French for banking, law, economics or medicine, where on-line resources are available.English, and more precisely CS English is, for our students, a necessary tool, and not an object of study. The learning activities must therefore stimulate the students' interest and reflection about language phenomena. Our pedagogical objective, relying on research acquisition (Wokusch 1997) consists in linking various texts together with other documents, such as different types of dictionaries or other types of texts, so that knowledge can be acquired using various appropriate contexts.Language teachers are not supposed to be experts in fields such as computer sciences or economics. We aim at helping them to make use of the authentic documents that are related to the subject area in which they teach English. As shown in Foucou and Kübler (1998) the wide range of resources available on the Web can be processed to obtain corpora, i.e. teaching material. Our Web-based environment therefore provides teachers with a series of tools which enable them to access information about the selected specialist subject, select appropriate specialised texts, produce various types of learning activities and evaluate students' progress.Commonly used textbooks Tor specialised English offer a wide range of learning activities, but they are based on documents that very quickly become obsolete, and that are sometimes widely modified. Moreover, they are not adaptable to the various levels of language of the students. From the students' point of view, working on obsolete texts that are either too easy or too difficult can quickly become demotivating, not to say boring.In the next section, we present the general architecture of the teaching/learning environment; the method of accessing and using it, for teachers as well as for students, is then described. The following section deals with the actual production of exercises and their limits. We conclude and present some possible research directions.

scholarly journals A Men Who Have Sex With Men–Friendly Doctor Finder Hackathon in Guangzhou, China: Development of a Mobile Health Intervention to Enhance Health Care Utilization (Preprint)

2019 ◽  
Author(s):  
Chunyan Li ◽  
Yuan Xiong ◽  
Hao Fong Sit ◽  
Weiming Tang ◽  
Brian J Hall ◽  
...  
Keyword(s):  
Public Health ◽  
Health Care ◽  
Social Media ◽  
Social Networking ◽  
Computer Science ◽  
Mobile Health ◽  
Clinical Medicine ◽  
Web Based ◽  
Mhealth Intervention ◽  
Sex With Men

BACKGROUND Mobile health (mHeath)–based HIV and sexual health promotion among men who have sex with men (MSM) is feasible in low- and middle-income settings. However, many currently available mHealth tools on the market were developed by the private sector for profit and have limited input from MSM communities. OBJECTIVE A health hackathon is an intensive contest that brings together participants from multidisciplinary backgrounds to develop a proposed solution for a specific health issue within a short period. The purpose of this paper was to describe a hackathon event that aimed to develop an mHealth tool to enhance health care (specifically HIV prevention) utilization among Chinese MSM, summarize characteristics of the final prototypes, and discuss implications for future mHealth intervention development. METHODS The hackathon took place in Guangzhou, China. An open call for hackathon participants was advertised on 3 Chinese social media platforms, including Blued, a popular social networking app among MSM. All applicants completed a Web-based survey and were then scored. The top scoring applicants were grouped into teams based on their skills and content area expertise. Each team was allowed 1 month to prepare for the hackathon. The teams then came together in person with on-site expert mentorship for a 72-hour hackathon contest to develop and present mHealth prototype solutions. The judging panel included experts in psychology, public health, computer science, social media, clinical medicine, and MSM advocacy. The final prototypes were evaluated based on innovation, usability, and feasibility. RESULTS We received 92 applicants, and 38 of them were selected to attend the April 2019 hackathon. A total of 8 teams were formed, including expertise in computer science, user interface design, business or marketing, clinical medicine, and public health. Moreover, 24 participants self-identified as gay, and 3 participants self-identified as bisexual. All teams successfully developed a prototype tool. A total of 4 prototypes were designed as a mini program that could be embedded within a popular Chinese social networking app, and 3 prototypes were designed as stand-alone apps. Common prototype functions included Web-based physician searching based on one’s location (8 prototypes), health education (4 prototypes), Web-based health counseling with providers or lay health volunteers (6 prototypes), appointment scheduling (8 prototypes), and between-user communication (2 prototypes). All prototypes included strategies to ensure privacy protection for MSM users, and some prototypes offered strategies to ensure privacy of physicians. The selected prototypes are undergoing pilot testing. CONCLUSIONS This study demonstrated the feasibility and acceptability of using a hackathon to create mHealth intervention tools. This suggests a different pathway to developing mHealth interventions and could be relevant in other settings.

scholarly journals PENERAPAN METODE SEMANTIK SEARCH DALAM SISTEM INFORMASI PENCARIAN DOKUMEN KERJA PRAKTEK DAN SKRIPSI BERBASIS WEB

2018 ◽  
Vol 3 (2) ◽  
pp. 83-88
Author(s):  
Mitra Unik
Keyword(s):  
Computer Science ◽  
Search Method ◽  
Semantic Search ◽  
Practical Work ◽  
Web Based ◽  
Engineering Faculty ◽  
Search Results

This writing discusses the making of the application search documents practical work and thesis in the Department of Informatics Engineering Faculty of Computer Science Univestias Muhammadiyah Riau. This web-based application uses semantic search method in its search results. This app is designed to generate relevant or easy-to-understand search words by students and also generate words related to search keywords. The goal is to facilitate students in finding reference documents working practice and thesis and to avoid similarity with the previous student topic.

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