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A model-theoretic Baire category theorem for simple theories and its applications

Ziv Shami (2013)

Fundamenta Mathematicae

We prove a model-theoretic Baire category theorem for τ ̃ l o w f -sets in a countable simple theory in which the extension property is first-order and show some of its applications. We also prove a trichotomy for minimal types in countable nfcp theories: either every type that is internal in a minimal type is essentially 1-based by means of the forking topologies, or T interprets an infinite definable 1-based group of finite D-rank or T interprets a strongly minimal formula.

A new approach to chordal graphs

Ladislav Nebeský (2007)

Czechoslovak Mathematical Journal

By a chordal graph is meant a graph with no induced cycle of length 4 . By a ternary system is meant an ordered pair ( W , T ) , where W is a finite nonempty set, and T W × W × W . Ternary systems satisfying certain axioms (A1)–(A5) are studied in this paper; note that these axioms can be formulated in a language of the first-order logic. For every finite nonempty set W , a bijective mapping from the set of all connected chordal graphs G with V ( G ) = W onto the set of all ternary systems ( W , T ) satisfying the axioms (A1)–(A5) is...

A new approach to representation of observables on fuzzy quantum posets

Le Ba Long (1992)

Applications of Mathematics

We give a representation of an observable on a fuzzy quantum poset of type II by a pointwise defined real-valued function. This method is inspired by that of Kolesárová [6] and Mesiar [7], and our results extend representations given by the author and Dvurečenskij [4]. Moreover, we show that in this model, the converse representation fails, in general.

A new class of weakly countably determined Banach spaces

K. K. Kampoukos, S. K. Mercourakis (2010)

Fundamenta Mathematicae

A class of Banach spaces, countably determined in their weak topology (hence, WCD spaces) is defined and studied; we call them strongly weakly countably determined (SWCD) Banach spaces. The main results are the following: (i) A separable Banach space not containing ℓ¹(ℕ) is SWCD if and only if it has separable dual; thus in particular, not every separable Banach space is SWCD. (ii) If K is a compact space, then the space C(K) is SWCD if and only if K is countable.

A new class of weakly K -analytic Banach spaces

Sophocles Mercourakis, E. Stamati (2006)

Commentationes Mathematicae Universitatis Carolinae

In this paper we define and investigate a new subclass of those Banach spaces which are K -analytic in their weak topology; we call them strongly weakly K -analytic (SWKA) Banach spaces. The class of SWKA Banach spaces extends the known class of strongly weakly compactly generated (SWCG) Banach spaces (and their subspaces) and it is related to that in the same way as the familiar classes of weakly K -analytic (WKA) and weakly compactly generated (WCG) Banach spaces are related. We show that: (i) not...

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