Definability
Mostrando 1-3 de 3 artigos, teses e dissertações.
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1. Expressiveness and definability in circumscription
We investigate expressiveness and definability issues with respect to minimal models, particularly in the scope of Circumscription. First, we give a proof of the failure of the Löwenheim-Skolem Theorem for Circumscription. Then we show that, if the class of P; Z-minimal models of a first-order sentence is Δ-elementary, then it is elementary. That is, whene
Manuscrito. Publicado em: 2011-06
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2. Minimal Model and hierarchy of expressive power / Modelos minimais e hierarquia de expressividade
Neste trabalho, o conceito de Modelo Minimal e seu uso na semÃntica de certas lÃgicas sÃo estudados. NÃs analisamos o poder expressivo de diversas lÃgicas que usam o conceito de Modelo Minimal para definir sua relaÃÃo de satisfaÃÃo. Os principais teoremas estudados foram o Teorema de LÃwenheim-Skolem e o Teorema de Definibilidade de Beth. No CapÃt
Publicado em: 2007
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3. Generalizing Fisher's "reproductive value": linear differential and difference equations of "dilute" biological systems.
R. A. Fisher's 1930 "reproductive value" is defined as the contribution made by a population's initial age elements to its asymptotically dominating exponential growth mode. For the Leslie discrete-time model, it is the characteristic row vector of the Leslie matrix, and for the integral-equation model of Lotka the similar eigenfunction. It generalizes neatl