Results 251 to 260 of about 759,634 (294)

t-closure Operators

International Journal of General Systems, 2018
In this study, based on the knowledge of the existence of t-norms on an arbitrary given bounded lattice, we introduce t-closure operators with the help of a t-norm on the lattice and a subset of th...
Mehmet Akif Ince, Funda Karaçal
openaire   +2 more sources

Closure operations in phylogenetics

Mathematical Biosciences, 2007
Closure operations are a useful device in both the theory and practice of tree reconstruction in biology and other areas of classification. These operations take a collection of trees (rooted or unrooted) that classify overlapping sets of objects at their leaves, and infer further tree-like relationships. In this paper we investigate closure operations
Grünewald, Stefan, Steel, Mike, Swenson, M. Shel   +2 more
openaire   +3 more sources

A CLOSURE OPERATION IN RINGS

International Journal of Mathematics, 2001
We study the operation E → cl (E) defined on subsets E of a unital ring R, where x ∈ cl (E) if (x + Rb) ∩ E ≠ ∅ for each b in R such that Rx + Rb = R. This operation, which strongly resembles a closure, originates in algebraic K-theory. For any left ideal L we show that cl (L) equals the intersection of the maximal left ideals of R containing L ...
Ara, P., Pedersen, Gert Kjærgård, Perera, F.   +2 more
openaire   +2 more sources

Regular closure operators

Applied Categorical Structures, 1994
In an \((E,{\mathcal M})\)-category \({\mathcal X}\) for sinks, we identify necessary conditions for Galois connections from the power collection of the class of (composable pairs) of morphisms in \({\mathcal M}\) to factor through the ``lattice'' of all closure operators on \({\mathcal M}\), and to factor through certain sublattices. This leads to the
Gabriele Castellini, Jürgen Koslowski, George E. Strecker   +2 more
openaire   +1 more source

Closure Operator Constructions Depending On One Parameter

Quaestiones Mathematicae, 2003
Let X be an (E, M)-category for sinks. For each subclass N of M, two new Galois connections that generalize the Clementino-Tholen connectedness and separation Galois connections are introduced.
David Holgate
exaly   +1 more source

Closure Operators for ROBDDs

2005
Program analysis commonly makes use of Boolean functions to express information about run-time states. Many important classes of Boolean functions used this way, such as the monotone functions and the Boolean Horn functions, have simple semantic characterisations.
Peter Schachte, Harald Søndergaard
openaire   +2 more sources

Openness with Respect to a Closure Operator

Applied Categorical Structures, 2000
The abstract notion of a closure operator \(c\) introduced by \textit{E. Giuli} and \textit{D. Dikranyan} [Topology Appl. 27, 129-143 (1987; Zbl 0634.54008)] permits to define easily the notion of \(c\)-closed map (loc. cit.). The authors study \(c\)-open maps [introduced by \textit{W. Tholen} and \textit{D.
Eraldo Giuli, Walter Tholen
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Closure Operators with Respect to a Functor

Applied Categorical Structures, 2001
For a functor \(U:{\mathcal A}\to X\) into a category \({\mathcal X}\) with a factorization structure, the paper introduces a categorical notion of closure operator for subobjects in \({\mathcal X}\) of objects of type \(UA\). When applied in the case that \(U\) is the identity functor, it coincides with the notion introduced by \textit{D.
Gabriele Castellini, Eraldo Giuli
openaire   +2 more sources

TOPOLOGICAL CATEGORIES AND CLOSURE OPERATORS

Quaestiones Mathematicae, 1988
Abstract It is shown that the category CS of closure spaces is a topological category. For each epireflective subcategory A of a topological category X a functor F A :X → X is defined and used to extend to the general case of topological categories some results given in [4], [5] and [10] for epireflective subcategories of the category Top of ...
Dikranjan D, Giuli E, TOZZI, Anna
openaire   +3 more sources

U-Closure Operators and Compactness

Applied Categorical Structures, 2005
In this paper the authors introduce a notion of compactness in the following way: Let \({\mathcal A}\) be a category, \(\chi \) a finitely complete category with a proper \((\varepsilon ,{\mathcal M})\)-factorization structure for morphisms and \(U:{\mathcal A}\rightarrow \chi \) a functor. A pair \((A,m)\) with \(A\) object of \({\mathcal A}\) and \(m:
Gabriele Castellini, Eraldo Giuli
openaire   +3 more sources