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On the concreteness of quantum logics

Pavel Pták, John David Maitland Wright (1985)

Aplikace matematiky

It is shown that for any quantum logic L one can find a concrete logic K and a surjective homomorphism f from K onto L such that f maps the centre of K onto the centre of L . Moreover, one can ensure that each finite set of compatible elements in L is the image of a compatible subset of K . This result is “best possible” - let a logic L be the homomorphic image of a concrete logic under a homomorphism such that, if F is a finite subset of the pre-image of a compatible subset of L , then F is compatible....

On the construction of dense lattices with a given automorphisms group

Philippe Gaborit, Gilles Zémor (2007)

Annales de l’institut Fourier

We consider the problem of constructing dense lattices in n with a given non trivial automorphisms group. We exhibit a family of such lattices of density at least c n 2 - n , which matches, up to a multiplicative constant, the best known density of a lattice packing. For an infinite sequence of dimensions n , we exhibit a finite set of lattices that come with an automorphisms group of size n , and a constant proportion of which achieves the aforementioned lower bound on the largest packing density. The algorithmic...

On the lattice of deductive systems of a BL-algebra

Dumitru Bu§neag, Dana Piciu (2003)

Open Mathematics

For a BL-algebra A we denote by Ds(A) the lattice of all deductive systems of A. The aim of this paper is to put in evidence new characterizations for the meet-irreducible elements on Ds(A). Hyperarchimedean BL-algebras, too, are characterized.

On the lattice of n-filters of an LM n-algebra

Dumitru Buşneag, Florentina Chirteş (2007)

Open Mathematics

For an n-valued Łukasiewicz-Moisil algebra L (or LM n-algebra for short) we denote by F n(L) the lattice of all n-filters of L. The goal of this paper is to study the lattice F n(L) and to give new characterizations for the meet-irreducible and completely meet-irreducible elements on F n(L).

On the Leibniz congruences

Josep Font (1993)

Banach Center Publications

The aim of this paper is to discuss the motivation for a new general algebraic semantics for deductive systems, to introduce it, and to present an outline of its main features. Some tools from the theory of abstract logics are also introduced, and two classifications of deductive systems are analysed: one is based on the behaviour of the Leibniz congruence (the maximum congruence of a logical matrix) and the other on the behaviour of the Frege operator (which associates to every theory the interderivability...

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