Dependent Object Types (DOT) is a calculus with path dependent types, intersection types, and object self-references, which serves as the core calculus of Scala 3. Although the calculus has been ...proven sound, it remains open whether type checking in DOT is decidable. In this paper, we establish undecidability proofs of type checking and subtyping of D <: , a syntactic subset of DOT. It turns out that even for D <: , undecidability is surprisingly difficult to show, as evidenced by counterexamples for past attempts. To prove undecidability, we discover an equivalent definition of the D <: subtyping rules in normal form. Besides being easier to reason about, this definition makes the phenomenon of subtyping reflection explicit as a single inference rule. After removing this rule, we discover two decidable fragments of D <: subtyping and identify algorithms to decide them. We prove soundness and completeness of the algorithms with respect to the fragments, and we prove that the algorithms terminate. Our proofs are mechanized in a combination of Coq and Agda.
We study the problem of assigning objects. There may be multiple copies of each object. Each agent is assigned at most one. Monetary transfer is not allowed. We require a rule to be fair and ...efficient. We introduce an axiom that is a natural weakening of no-envy. We call it “bounded no-envy”. It states that for each pair of agents who receive objects of the same rank in their respective preferences, each of them should find his assignment at least as desirable as the other’s. Bounded no-envy is compatible with Pareto efficiency. In particular, the immediate acceptance rules (a.k.a. the “Boston mechanisms”) satisfy both. Our main result is that the immediate acceptance rules are the only rules satisfying weak non-wastefulness, bounded no-envy, rank-respecting invariance, resource monotonicity, and bilateral consistency.
•We study the problem of assigning objects.•We introduce a fairness axiom called “bounded no-envy”.•Bounded no-envy is compatible with Pareto efficiency.•We study the logical relations between bounded no-envy and favoring higher ranks.•Our main result is a characterization of the immediate acceptance rules.
Dependent Object Types (DOT) is intended to be a core calculus for modelling Scala. Its distinguishing feature is abstract type members, fields in objects that hold types rather than values. Proving ...soundness of DOT has been surprisingly challenging, and existing proofs are complicated, and reason about multiple concepts at the same time (e.g. types, values, evaluation). To serve as a core calculus for Scala, DOT should be easy to experiment with and extend, and therefore its soundness proof needs to be easy to modify. This paper presents a simple and modular proof strategy for reasoning in DOT. The strategy separates reasoning about types from other concerns. It is centred around a theorem that connects the full DOT type system to a restricted variant in which the challenges and paradoxes caused by abstract type members are eliminated. Almost all reasoning in the proof is done in the intuitive world of this restricted type system. Once we have the necessary results about types, we observe that the other aspects of DOT are mostly standard and can be incorporated into a soundness proof using familiar techniques known from other calculi.
Using the computerized application of Modeling using Object Types (MOT) theory, this article examines the normative dimension of official interpretations of a corpus of core “communication rights” ...(the right to freedom of opinion and expression, the right to privacy, the right to participate in cultural life, and the right to education) enshrined and protected by the International Covenants on Human Rights. This article proposes a methodological contribution whereby the computerized application of knowledge modeling theory promotes the analysis and popularization of international human rights standards. Research findings draw attention to significant conceptual deficiencies included as part of international human rights standards. These deficiencies undermine the applicability of these standards and their relative usefulness in the context of complex sociopolitical issues relating to communication. In addition, this article underscores the need for communication rights studies to further integrate contributions from the field of international human rights law research. It demonstrates that interdisciplinary dialogue can open up new research agendas for communication rights scholars and contribute to a renewed critical analysis of international human rights standards.
Using the computerized application of Modeling using Object Types (MOT) theory, this article examines the normative dimension of official interpretations of a corpus of core “communication rights” ...(the right to freedom of opinion and expression, the right to privacy, the right to participate in cultural life, and the right to education) enshrined and protected by the International Covenants on Human Rights. This article proposes a methodological contribution whereby the computerized application of knowledge modeling theory promotes the analysis and popularization of international human rights standards. Research findings draw attention to significant conceptual deficiencies included as part of international human rights standards. These deficiencies undermine the applicability of these standards and their relative usefulness in the context of complex sociopolitical issues relating to communication. In addition, this article underscores the need for communication rights studies to further integrate contributions from the field of international human rights law research. It demonstrates that interdisciplinary dialogue can open up new research agendas for communication rights scholars and contribute to a renewed critical analysis of international human rights standards.
Purpose
The purpose of this paper is to present a way of working with open-standard building information modeling (BIM), object type libraries, systems engineering and an Information Delivery Manual ...for the management of information over the life-cycle of infrastructure assets. The concept is presented as a source of inspiration, proof of concept and to underpin the value of different parts of the concept leading to an integrated approach to life-cycle information management.
Design/methodology/approach
The paper presents a concept for a way of working. A proof of concept is provided in the form of a case study in which this concept is operational. It shows that this way of working using open-standard BIM can be applied to manage information in the life-cycle. It does not provide, nor suggest to provide, empirical evidence for specific benefits in terms of efficiency.
Findings
The paper shows that open-standard BIM can be applied for information management in the life-cycle of (construction) assets. The specific approach that is applied in practice in a Dutch Infrastructure Project is explained including a case project.
Research limitations/implications
The example of Traverse Dieren attests to a implementation of the approach in practice. From this case it can be concluded that the suggested approach is feasible in the initiation and design phase and applicable during realization. Based on the example as described in this paper it cannot be concluded to what extent the known information management problems in the life-cycle are solved. Therefore a detailed evaluation on the information exchange would be required which is beyond the scope of this paper.
Practical implications
This paper shows how different (theoretical) concepts are successfully combined and implemented in practice to attain the defined BIM goals.
Originality/value
This paper shows a practical case implementation of open-standard BIM (using COINS). It provides a way of working that combines BIM, systems engineering, libraries and contractual arrangements for the management of information over the life-cycle of infrastructure assets.
Aims and research questions:
This paper presents a new study addressing the issue of cross-linguistic influence in acquisition of referring expressions. The main research question is how to predict ...directionality of this influence in a dual language development.
Methodology:
The method is an elicited production task. We consider the phenomenon of direct object referring choices, i.e. noun, pronoun and null element, in a ‘null-object’–‘overt-object’ language pair (Ukrainian and English).
Data and Analysis:
Participants of the experiment are 4–6-year-old Ukrainian–English bilinguals (N20) and Ukrainian monolinguals (N21). The data are analyzed in the statistical program R, utilizing the R-library function lme4. The results are presented as odds ratios (ORs) of each direct object type.
Findings:
Our data reveal that while there is no significant difference in Ukrainian object types in most of the age groups, there is a considerable amount of null object usage in English at the ages of four to five.
Originality:
The innovative nature of this study lies in: (i) the consideration of a licit object omission at a later stage of language development (from 4 to 6 years of age); (ii) the examination of an under-investigated language combination (i.e. English and Ukrainian); and (iii) the innovative approach to linguistic data analysis (e.g. comparing OR values).
Implications:
Our findings suggest that the directionality of influence in dual language acquisition depends on the developmental stage, language-specific means of syntax–pragmatics interaction, and extra-linguistic input-related factors. At the early stages of development, the null-object language is likely to influence the overt-object language, especially under conditions of limited exposure to the latter.
The dynamics of the actual global context create a growing need for creation of better knowledge management in organizations. More than ever global markets exercise a bottom-up pressure (market ...dynamics and daily practices) and a top-down pressure (standardization) on employees who must constantly create, acquire and disseminate new knowledge. Due to this, employees engage sometimes in workarounds that defy the standardization of expected performance. However, given that workarounds are deliberate actions in contrast with the prescribed practices, they are marginalized by organizations that perceive them as detrimental. In this paper, we propose a theoretical framework that is based on the idea that the integration of workarounds in the workplace represents a process of knowledge management. It also suggests that the use of a socio-technological tool that allows the building and sharing of workarounds by employees will help foster the creation and updating of knowledge in the organizational memory.
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