拟半连续格和交半连续格

作为半连续格的推广, 引入了拟半连续格的概念. 讨论了拟半连续格的基本性质. 在拟半连续格上得到了类似于拟连续偏序集的一些主要结果. 同时探讨了半连续格、拟半连续格、交半连续格、交连续格、强连续格几种不同结构之间的关系. 最后,讨论了半连续函数空间仍是半连续格的条件.     

分配格与模格的另一二条件等价定义

针对分配格与模格的格等式定义问题,得知了二条件是定义分配格与模格的最少条件,并进一步证明了Sholander's basis是定义分配格的最短最少变量格等式,最后又从分配格和模格的基本定义出发给出了新的分配格的二条件和三条件等价定义等式及模格的二条件与三条件等价定义等式.     

剩余格与正则剩余格的特征定理

本文进一步研究了具有广泛应用的一类模糊逻辑代数系统——剩余格，并引入了正则剩余格的概念，对剩余格与正则剩余格的定义进行了讨论，给出了剩余格与正则剩余格的特征定理，其中包含剩余格与正则剩余格的等式特征，从而这两个格类都构成簇．本文还讨论了剩余格与正则剩余格公理系统的独立性，以及它们与相近代数结构的关系．     

Semicontinuous lattices

In this paper we introduce and study a new type of lattices, semicontinuous lattices, by using semiprime ideals. Such lattices have many properties similar to that of continuous lattices, and are closely related to the theory of continuous lattices. Received November 3, 1995; accepted in final form March 13, 1997.     

Well-rounded algebraic lattices in odd prime dimension

Well-rounded lattices have been considered in coding theory, in approaches to MIMO, and SISO wiretap channels. Algebraic lattices have been used to obtain dense lattices and in applications to Rayleigh fading channels. Recent works study the relation between well-rounded lattices and algebraic lattices, mainly in dimension two. In this article we present a construction of well-rounded algebraic lattices in Euclidean spaces of odd prime dimension. We prove that for each Abelian number field of odd prime degree having squarefree conductor, there exists a $${\mathbb {Z}}$$ -module M such that the canonical embedding applied to M produces a well-rounded lattice. It is also shown that for each odd prime dimension there are infinitely many non-equivalent well-rounded algebraic lattices, with high indexes as sublattices of other algebraic lattices.     

Geometric exchange properties in lattices of finite length

We investigate geometric exchange properties in lattices of finite length that generalize the Steinitz exchange property of finite-dimensional vector spaces. In particular, we show that a stronger version of MacLane's exchange property for semimodular lattices is equivalent to the join-symmetric exchange property of Gaskill and Rival for modular lattices and, furthermore, that this exchange property characterizes strong semimodular lattices. An analogue of the basis exchange property for matroids is considered and seen to distinguish strong lattices in the class of semimodular lattices.Presented by I. Rival.     

Cones,semicontinuous functions,and continuous lattices

The purpose of this paper is to introduce a notion which is a generalization of convex sets and to use this notion to construct continuous lattices which are shown to be related to lattices of lower-semicontinuous functions. The end results of this development is a characterization of lattices of lower-semicontinuous functions in terms of a class of continuous lattices introduced in this paper (see Theorem 8). Then material is introduced which leads to a complementary result in Theorem 11 which characterizes the continuous lattices that can be lattices of lower-semicontinuous functions.     

Coalgebraic representations of distributive lattices with operators

We present a framework for extending Stone's representation theorem for distributive lattices to representation theorems for distributive lattices with operators. We proceed by introducing the definition of algebraic theory of operators over distributive lattices. Each such theory induces a functor on the category of distributive lattices such that its algebras are exactly the distributive lattices with operators in the original theory. We characterize the topological counterpart of these algebras in terms of suitable coalgebras on spectral spaces. We work out some of these coalgebraic representations, including a new representation theorem for distributive lattices with monotone operators.     

Sums of Lattices and a Relational Category

We introduce a new relational category of lattices, and an analogous category of complete lattices. These categories allow us to construct sums of (complete) lattices. While previous constructions used two functors (or, for complete lattices, a single functor that had an adjoint), we need only a single functor (and no additional property when complete lattices are considered). In the finite case, the present construction is easy to visualize.     

Z-半连续格

作为连续格和半连续格的公共推广,引入了广义理想子系统Z、Z-半连续格及强Z-连续格的概念,讨论了它们的基本性质和Z-半连续格的函数空间的结构,给出了强Z-连续格到方体的嵌入,证明了当子系统Z满足一定条件时,Z-半连续格范畴SCLZ是笛卡儿闭的。     

Interpolation on lattices generated by cubic pencils

Principal lattices are distributions of points in the plane obtained from a triangle by drawing equidistant parallel lines to the sides and taking the intersection points as nodes. Interpolation on principal lattices leads to particularly simple formulae. These sets were generalized by Lee and Phillips considering three-pencil lattices, generated by three linear pencils. Inspired by the addition of points on cubic curves and using duality, we introduce an addition of lines as a way of constructing lattices generated by cubic pencils. They include three-pencil lattices and then principal lattices. Interpolation on lattices generated by cubic pencils has the same good properties and simple formulae as on principal lattices. Dedicated to C.A. Micchelli for his mathematical contributions and friendship on occasion of his sixtieth birthday Mathematics subject classifications (2000) 41A05, 41A63, 65D05. J.M. Carnicer: Partially supported by the Spanish Research Grant BFM2003-03510, by Gobierno de Aragón and Fondo Social Europeo.     

A non commutative generalization of *-autonomous lattices

Pseudo *-autonomous lattices are non-commutative generalizations of *-autonomous lattices. It is proved that the class of pseudo *-autonomous lattices is a variety of algebras which is term equivalent to the class of dualizing residuated lattices. It is shown that the kernels of congruences of pseudo *-autonomous lattices can be described as their normal ideals. The work on the paper was supported by grant of Czech Government MSM 6198959214.     

Primes,irreducibles and extremal lattices

This paper studies certain types of join and meet-irreducibles called coprimes and primes. These elements can be used to characterize certain types of lattices. For example, a lattice is distributive if and only if every join-irreducible is coprime. Similarly, a lattice is meet-pseudocomplemented if and only if each atom is coprime. Furthermore, these elements naturally decompose lattices into sublattices so that often properties of the original lattice can be deduced from properties of the sublattice. Not every lattice has primes and coprimes. This paper shows that lattices which are long enough must have primes and coprimes and that these elements and the resulting decompositions can be used to study such lattices.The length of every finite lattice is bounded above by the minimum of the number of meet-irreducibles (meet-rank) and the number of join-irreducibles (join-rank) that it has. This paper studies lattices for which length=join-rank or length=meet-rank. These are called p-extremal lattices and they have interesting decompositions and properties. For example, ranked, p-extremal lattices are either lower locally distributive (join-rank=length), upper locally distributive (meet-rank=length) or distributive (join-rank=meet-rank=length). In the absence of the Jordan-Dedekind chain condition, p-extremal lattices still have many interesting properties. Of special interest are the lattices that satisfy both equalities. Such lattices are called extremal; this class includes distributive lattices and the associativity lattices of Tamari. Even though they have interesting decompositions, extremal lattices cannot be characterized algebraically since any finite lattice can be embedded as a subinterval into an extremal lattice. This paper shows how prime and coprime elements, and the poset of irreducibles can be used to analyze p-extremal and other types of lattices.The results presented in this paper are used to deduce many key properties of the Tamari lattices. These lattices behave much like distributive lattices even though they violate the Jordan-Dedekind chain condition very strongly having maximal chains that vary in length from N-1 to N(N-1)/2 where N is a parameter used in the construction of these lattices.     

Parallel axiom in convexity lattices

The convexity lattices, introduced by Bennett and Birkhoff, generalize the lattices of convex sets. We present three forms of Parallel Axiom in such lattices and define Euclidean and two classes of non-Euclidean lattices via the number of parallel lines through a point. The paper deals with these three classes of lattices.     

Covering aspects of the Niemeier lattices

The Niemeier lattices are the 23 unimodular even lattices of norm 2 in dimension 24. We determine computationally their covering radius for 16 of those lattices and give lower bounds for the remaining that we conjecture to be exact. This is achieved by computing the list of Delaunay polytopes of those lattices.     

Some remarks concerning the infinite distributivity of lattices

Theorems are proved concerning the regular imbedding of an infinitely distributive lattice in least decomposable lattices and in completely decomposable lattices. A relation is established between decomposable lattices, Stone lattices, and completely decomposable lattices.Translated from Matematicheskie Zametki, Vol. 8, No. 1, pp. 95–103, July, 1970.We use this opportunity to thank A. G. Pinsker for his valuable advice concerning this work.     

Intersecting antichains and shadows in linear lattices

We establish a homomorphism of finite linear lattices onto the Boolean lattices via a group acting on linear lattices. By using this homomorphism we prove the intersecting antichains in finite linear lattices satisfy an LYM-type inequality, as conjectured by Erd?s, Faigle and Kern, and we state a Kruskal-Katona type theorem for the linear lattices.