In simply typed λ-calculus with one ground type the following theorem due to Loader holds. (i) Given the full model F over a finite set, the question whether some element f ∈ F is λ-definable is undecidable. In the λ-calculus with intersection types based on countably many atoms, the following is proved by Urzyczyn. (ii) It is undecidable whether a type is inhabited. Both statements are major r...

This paper presents a protocol for efficient transaction management in an environment of replicated autonomous databases. Each replicated copy has ownership over mutually exclusive portions of the database. The protocol improves response time and throughput by exploiting parallelism although reducing the degree of transaction isolation. Most modifications to the database are assumed to be on th...

Currently, adaptive educational hypermedia systems (AEHS) are described with nonuniform methods, depending on the specific view on the system, the application, or other parameters. There is no common language for expressing functionality of AEHS, hence these systems are difficult to compare and analyze. In this paper we investigate how a logical description can be employed to characterize adapt...

This paper focuses on inconsistencies arising from the use of NPV and CAPM for capital budgeting. It shows that (i) CAPM capital budgeting decision-making based on disequilibrium NPV is deductively inferred by the Capital Asset Pricing Model, (ii) the use of the disequilibrium NPV is widespread in finance both as a decision rule and as a valuation tool, (iii) the disequilibrium NPV does not gua...

In networked cyber physical systems real time global computations, e.g., the supervisory control of a flight control system, require consistent views, consistent actions and synchronized state transitions across network nodes in real time. This paper presents a real time logical synchrony protocol, Physically Asynchronous Logically Synchronous (PALS), to support real time global computation. Un...

In our previous work, we developed a reversible programming language and established that every computation in it is a (partial) isomorphism that is reversible and that preserves information. The language is founded on type isomorphisms that have a clear categorical semantics but that are awkward as a notation for writing actual programs, especially recursive ones. This paper remedies this aspe...

Framing effects are said to occur when equivalent frames lead to different choices. However, the equivalence in question has been incompletely conceptualized. In a new normative analysis of framing effects, we complete the conceptualization by introducing the notion of information equivalence. Information equivalence obtains when no choice-relevant inferences can be drawn from the speaker s cho...

In simply typed λ-calculus with one ground type the following theorem due to Loader holds. (i) Given the full model F over a finite set, the question whether some element f ∈ F is λ-definable is undecidable. In the λ-calculus with intersection types based on countably many atoms, the following is proved by Urzyczyn. (ii) It is undecidable whether a type is inhabited. Both statements are major r...

We deilne the logically synchronous muliirast problem, which imposes a natura] and useful structure on message delivery order in an asynchronous system. In this problem, a computation proceeds by a sequence of rnulticasts, in which a process sends a message to some arbitrary subset of the processes, including itselL A logically synchronous rnu1tcast protocol must make t appear to ever) process ...

We provide an algebraic characterization of the expressive power of various naturally defined logics on finite trees. These logics are described in terms of Lindström quantifiers, and particular cases include first-order logic and modular logic. The algebraic characterization we give is expressed in terms of a new algebraic structure, finitary preclones, and uses a generalization of the block p...