Decidable Subtyping for Path Dependent Types

<p>Path dependent types form a central component of the Scala programming language. Coupled with other expressive type forms, path dependent types provide for a diverse set of concepts and patterns, from nominality to F-bounded polymorphism. Recent years have seen much work aimed at formalising the foundations of path dependent types, most notably a hard won proof of type safety. Unfortunately subtyping remains undecidable, presenting problems for programmers who rely on the results of their tools. One such tool is Dotty, the basis for the upcoming Scala 3. Another is Wyvern, a new programming language that leverages path dependent types to support both first class modules and parametric polymorphism. In this thesis I investigate the issues with deciding subtyping in Wyvern. I define three decidable variants that retain several key instances of expressiveness including the ability to encode nominality and parametric polymorphism. Wyvfix fixes types to the contexts they are defined in, thereby eliminating expansive environments. Wyvnon-μ removes recursive subtyping, thus removing the key source of expansive environments during subtyping. Wyvμ places a syntactic restriction on the usage of recursive types. I discuss the formal properties of these variants, and the implications each has for expressing the common programming patterns of path dependent types. I have also mechanized the proofs of decidability for both Wyvfix and Wyvμ in Coq.</p>

Decidable Subtyping for Path Dependent Types

<p>Path dependent types form a central component of the Scala programming language. Coupled with other expressive type forms, path dependent types provide for a diverse set of concepts and patterns, from nominality to F-bounded polymorphism. Recent years have seen much work aimed at formalising the foundations of path dependent types, most notably a hard won proof of type safety. Unfortunately subtyping remains undecidable, presenting problems for programmers who rely on the results of their tools. One such tool is Dotty, the basis for the upcoming Scala 3. Another is Wyvern, a new programming language that leverages path dependent types to support both first class modules and parametric polymorphism. In this thesis I investigate the issues with deciding subtyping in Wyvern. I define three decidable variants that retain several key instances of expressiveness including the ability to encode nominality and parametric polymorphism. Wyvfix fixes types to the contexts they are defined in, thereby eliminating expansive environments. Wyvnon-μ removes recursive subtyping, thus removing the key source of expansive environments during subtyping. Wyvμ places a syntactic restriction on the usage of recursive types. I discuss the formal properties of these variants, and the implications each has for expressing the common programming patterns of path dependent types. I have also mechanized the proofs of decidability for both Wyvfix and Wyvμ in Coq.</p>

Predicting mental health status in remote and rural farming communities: An analysis of text-based counselling transcripts (Preprint)

BACKGROUND Australians living in rural and remote areas are at elevated risk of mental health problems, and must overcome barriers to help-seeking, such as poor access, stigma and entrenched stoicism. E-mental health services circumvent such barriers using technology, and text-based services are particularly well suited to clients concerned with privacy and self-presentation. They allow the client to reflect on the therapy session after it has ended as the transcript is stored on their device. The text transcript also offers researchers an opportunity to analyse language use patterns and explore how these relate to mental health status. OBJECTIVE In this project, we investigated whether computational linguistic techniques can be applied to text-based communications with the goal of identifying a client’s mental health status. METHODS Client-therapist text message transcripts were analysed using the Linguistic Inquiry and Word Count tool. We examined whether the resulting word counts related to the participants’ presenting problems or their self-ratings of mental health at the conclusion of counselling. RESULTS The results confirmed that word use patterns could be used to differentiate whether a client had one of the top three presenting problems (depression, anxiety, or stress), as well as prospectively to predict their self-rated mental health after counselling had concluded. CONCLUSIONS These findings suggest that language use patterns are useful both for researchers and for clinicians trying to identify individuals at risk of mental health problems, with potential applications in screening and targeted intervention.

Dysphagia, dyspepsia, and hiccups

Dysphagia, or difficulty swallowing, is a complex problem. Although patients may present with dysphagia as an issue that requires palliation, other patients may develop dysphagia as a complication of progressive disease and increasing debilitation. The diagnosis of dyspepsia requires patients to be experiencing one or more of the following four problems: epigastric pain, epigastric burning, postprandial fullness, or early satiety. Dyspepsia may occur either as a functional disorder where the cause is not clear or as a secondary disorder. Hiccup, or more correctly, singultus, is a problem where patients experience a sharp and involuntary contraction of the muscles of inspiration which cause a sudden sharp inspiration and closure of the glottis. For most, this is a short-lived experience. This chapter discusses the definition, prevalence, pathophysiology, causes, presenting problems, investigations, and management of dysphagia, dyspepsia, and hiccups.

Delivery of Standard UP-C and UP-A Treatment for Youth with Emotional Disorders

This chapter describes the standard delivery of the Unified Protocols for Transdiagnostic Treatment of Emotional Disorders in Children and Adolescents (UP-C and UP-A). It is intended to help therapists understand how the flexible modules within each treatment are typically presented, and serves to supplement the existing UP-C/A therapist guide. This chapter outlines the core transdiagnostic treatment components that are common to the UP-C and UP-A while also highlighting key differences in treatment presentation for different developmental levels to help therapists select the most appropriate intervention for their clients. While this chapter focuses on the delivery of UP-C and UP-A for youth with depression, anxiety, and related concerns, it also provides greater context for treatment adaptations for other presenting problems that are described later in this book.

Scope of the Issue

The worldwide frequency of sexual assault and the associated psychosocial difficulties have led to sexual violence being deemed a serious public health issue. There is a growing understanding in the field that survivors’ outcomes following sexual assault follow unique trajectories and professionals need to conduct thorough, unbiased assessment to adequately capture survivors’ presenting problems and their person-specific contributing factors. Although survivors are increasingly disclosing their victimization, they still experience obstacles to reporting victimization and receiving services. For example, many survivors report that formal sources of support are unhelpful or even potentially harmful. With the goal of increasing access to affirming and supportive services, the remaining chapters of this book highlight many of the common issues that emerge when working with sexual assault survivors and cover best practices for receiving disclosures of sexual assault.

Analisis interpretasi matematis dalam mini riset mahasiswa melalui pembelajaran berbasis riset

Statistics are studied in many fields of study including in Governmental Science, University of Muhammadiyah Malang (UMM). However, in reality, many UMM Government Science students do not understand the material and still have difficulty applying statistical methods, so it is necessary to provide mini research-based learning and analysis of interpretation abilities. The purpose of this research was to analyze students’ interpretative abilities in mini-research on research-based learning. The research used a qualitative descriptive method. The research sample consisted of 1 student who carried out mini research-based learning. The results of student’s reports were analyzed according to the indicators of interpretation ability. The result of the research indicated that the application of research-based learning in statistics subjects has a positive impact on students’ mathematical interpretation abilities can be seen from the achievement of the mathematical representation indicators found in the mini-research conducted by subject 1 in class. However, several things need to be improved in the mini-research conducted by subject 1, namely presenting problems and solving them in other forms. The descriptor wrote the notation in other forms and communicates the notation according to the idea.

Integrating Technology into School-Based Interventions

Cognitive behavioral therapy (CBT) was formulated well before the first cellphone hit the market, but computer- and smartphone-assisted applications are increasingly popular. Chapter 8 reviews the rationale for incorporating technology into CBT and the research supporting it. It includes detailed considerations for selecting mobile apps for behavior change, mindfulness, and therapy/self-help goals and offers advice on how to utilize them with students and teachers. Select apps are described in detail, along with their pros and cons and utility for specific presenting problems. The chapter concludes by acknowledging some limitations of mobile apps and presenting a case study that applies mobile apps in a school-based session.