Solving constrained Horn clauses modulo algebraic data types and recursive functions

This work addresses the problem of verifying imperative programs that manipulate data structures, e.g., Rust programs. Data structures are usually modeled by Algebraic Data Types (ADTs) in verification conditions. Inductive invariants of such programs often require recursively defined functions (RDFs) to represent abstractions of data structures. From the logic perspective, this reduces to solving Constrained Horn Clauses (CHCs) modulo both ADT and RDF. The underlying logic with RDFs is undecidable. Thus, even verifying a candidate inductive invariant is undecidable. Similarly, IC3-based algorithms for solving CHCs lose their progress guarantee: they may not find counterexamples when the program is unsafe. We propose a novel IC3-inspired algorithm Racer for solving CHCs modulo ADT and RDF (i.e., automatically synthesizing inductive invariants, as opposed to only verifying them as is done in deductive verification). Racer ensures progress despite the undecidability of the underlying theory, and is guaranteed to terminate with a counterexample for unsafe programs. It works with a general class of RDFs over ADTs called catamorphisms. The key idea is to represent catamorphisms as both CHCs, via relationification , and RDFs, using novel abstractions . Encoding catamorphisms as CHCs allows learning inductive properties of catamorphisms, as well as preserving unsatisfiabilty of the original CHCs despite the use of RDF abstractions, whereas encoding catamorphisms as RDFs allows unfolding the recursive definition, and relying on it in solutions. Abstractions ensure that the underlying theory remains decidable. We implement our approach in Z3 and show that it works well in practice.

The Dialectics of Political Ideology and Power Relations in African Literature: A Reading of Adébáyọ̀ Fálétí’s Baṣọ̀run Gáà

Introduction Ideology underscores how we make sense of history and reality. It is the underlying theory that governs every organized movement, institution, and government. In Politics, ideology superintends the constructs, subversions, moderations, and resistance of power. In Literature, ideology plays even a deluxe role as it is the vehicle that drives political and cultural purposes. A close consideration of the African creative canvass reveals that her imaginative writings are burdened with the ideology of socio-cultural redemption. Although replete with a recasting of themes that stress the subversions and resistance of political and religious power, especially in the continent’s post-colonial space, there is not much thematic commitment among creative writers to the ideology that constructs and moderates power. Using the New Historicism as the theoretical basis, this paper proposes that to understand the logic that has bedeviled post-colonial African governance, there is need to revisit power structures that characterize the continent’s pre-colonial history. It is in this burden that this paper shall attempt to examine the dialectics of political ideology, power relations and the prophetic in Baṣọrun Gáà ̀. The paper also argues that the private anxieties of the playwright, as presented in the play, 160 Lere Adeyemi are prophetic in nature and that Baṣọrun Gáà is weakened by the burdens of ̀ his strength, in other words, blinded by sight.

Derogatory terms in free indirect discourse

Free indirect discourse (FID) is a style of reporting speech and thought that combines third-personal narration with direct, first-personal discourse. Expressive terms, such as “idiot” or “asshole”, are known to occur in FID. When so used, the pejorative content reflects the protagonist’s rather than the narrator’s point of view. This chapter broadens the discussion of derogatory terms in FID by investigating occurrences of slurring terms, such as the N-word. The two main approaches to FID, namely the two-context approach and the mixed-quotation approach, are discussed in light of these novel findings. The chapter shows that both are able to account for the data; however, the choice between them imposes constraints on the underlying theory of derogatory terms.

A Study of Speech Styles Used by the Host in Mata Najwa and Catatan Najwa

I conducted this study to investigate speech styles used by Najwa as the host in Mata Najwa Part 8 - Republik Digital: Bisnis Digital dan Peluangnya, Mata Najwa Part 9 - Republik Digital: Tips Membangun Bisnis Digital, and Catatan Najwa Part 2 - Ide-Ide Brilian Bos Sido Muncul to the younger and older guests. The underlying theory used is Speech Style from Chaer and Agustina (2010) and Indonesian: Standard Indonesian (Bahasa Baku) and Non-standard Indonesian (Bahasa Tidak Baku) from Prihantini (2015). This study was done using a qualitative approach. The data analysis revealed that Najwa as the host of Mata Najwa and Catatan Najwa, used formal style, consultative style, casual style, and intimate style when talking to her younger and older guests. Najwa did not use the frozen style when talking to her guests. Keywords: speech styles, age, host, talk show

On the existence and evaluation of Stokes phenomena in fluid mechanics

A singularly perturbed, high order KdV-type model, which describes localized travelling waves (“solitons”) is being considered. We focus on the Inner solution, and detect Stokes phenomena that are crucial as to whether we can obtain a suitable solution. We provide a simple proof that the corresponding Stokes constant is non-zero. Also, we evaluate this splitting constant numerically by using two methods that are induced by the underlying theory.

Democracy and the Quality of Government

Does democracy reduce corruption and improve quality of government? While the corruption-reducing effect of democracy may be seemingly self-evident in light of theoretical expectations, a wealth of empirical literature suggests that democracy is not always as effective as theories predict. Studies consistently demonstrate that newly democratized countries exhibit, on average, higher levels of corruption than more established democracies but also than some autocracies. This chapter takes stock of recent advances in efforts to understand how, whether, and when democracy contributes to weeding out corrupt leaders and government corruption more generally. While research has made notable advances, we suggest that a closer examination of the underlying theory of change and assumptions upon which the beneficial effects of democracy rest can identify new ways forward. We point to a need for greater attention to how, for example, state capacity, transparency, and experiences with different forms of corruption influence civic and electoral engagement against corruption.

17. Witness Statements and Documentary Evidence

Cases can readily be won or lost on the strength of witness evidence at trial. Important applications may fail if a witness statement does not adequately deal with all of the issues. A legal representative, therefore, must understand both the underlying theory behind the use of witness evidence and documentation during the course of litigation, including the rules on hearsay, and the practical requirements and challenges encountered in the preparation of witness statements. This chapter discusses the use of evidence at trial; the preparation of witness statements for interim applications and at trial; the use of hearsay in civil cases; and evidential tools.

The study about developing methodology of investigation of оrientation on communicative activity

Проблема коммуникативной активности человека становится чрезвычайно актуальной в связи с трансформацией прежних констант общения в современных условиях меняющегося мира; возникает потребность в создании психологического инструментария для изучения этой активности. В статье представлены результаты авторской разработки методики изучения направленности коммуникативной активности, ее теоретический и психометрический анализ. Теоретической предпосылкой создания методики изучения направленности коммуникативной активности является концептуальное представление о функциях человека как субъекта общения (В.Н. Панферов). Исходными теоретическими положениями послужили также идеи активности человека, заложенные в концепции интегральной индивидуальности (В.С. Мерлин); полифонии активности в концепции метаиндивидуального мира (Л.Я. Дорфман); интегративный подход к коммуникативной активности (С.А. Васюра). Методика выявляеткоммуникативную, информационную, когнитивную, эмотивную, конативную, креативную направленность активности человека, реализующуюся в непосредственном и Интернет-общении. На выборке 418 человек 17 - 25 лет (128 юношей, 290 девушек) обсуждены результаты валидизации методики. Доказано, что методика обладает прогностической ценностью при изучении круга явлений, относящихся к непосредственному и опосредованному (виртуальному) общению, а также к коммуникативному потенциалу личности. Методика изучения направленности коммуникативной активности может применяться в научных и прикладных исследованиях. The problem of a person's communicative activity becomes urgent due to the transformation of previous communication constants in the current conditions of the changing world, there is a need for development of psychological tools for this activity. The article contains results of developing methodology of investigation of оrientation on communicative activity, its theoretical and psychometric analysis. The theoretical premise of the methodology is the conceptual idea of human's functions as a subject of communication (V.N. Panferov). The ideas of human's activity that is a part of integrated individuality concept (V.S. Merlin), polyphony of activity in the concept of metainividual world (L.Ya. Dorfman), integrative approach to communicative activity (S.A. Vasyura) have become the underlying theory. The methodology examines communicative, informational, cognitive, emotive, conative, creative оrientation on a person's activity that implements in the direct Internet-communication. Results of methodology's validation are discussed on a sample of 418 people 17 - 25 aged (128 males, 290 females). The research has a predictive value in examining a range of features referring to both direct and indirect (virtual) communication, as well as a person's communicative potential. This study can be used in scientific and applied researches.

Ambivalence in Wieteke Van Dort’s Geef Mij Maar Nasi Goreng

This research focuses on how ambivalence works within the case of a Surabaya born singer, Wieteke Van Dort through her song Geef Mij Maar Nasi Goreng. The colonial power that lasted the longest time in today Indonesia was the Dutch administration. The Dutch people living in this area, experienced ambivalence, as the result of the challenging condition and the process of adaption where it was completely enigma to the condition of the motherland. Therefore, this study is conducted as a challenge to dichotomy of western vs eastern division in which extremely opposes each other. This research was descriptive qualitative in nature. The theory of ambivalence proposed by Homi Bhabha was used as an underlying theory. Postcolonial approach was also applied in analyzing Wieteke Van Dort’s ambivalence. The data were in the form of lyrics of a song entitled Geef Mij Maar Nasi Goreng. The research findings prove that through the lyrics of Geef Mij Maar Nasi Goreng, Wieteke Van Dort experiences ambivalence through her complex feeling in being attracted to her “native” Surabaya and her repulsion on the inferior Javanese culture. The research also shows that the western people, through the life of Wieteke Van Dort through her song Geef Mij Maar Nasi Goreng, experience ambivalence. It challenges the notion of nativeness in a sense that Wieteke Van Dort, as a native of Surabaya by birth, is ironically rejected by the other natives because of the judgment by blood. Western people, represented by Wieteke Van Dort, truly experience ambivalence.