关于有1模格的等价定义

进一步讨论有1模格的等价定义问题,得到并证明了一个(2,2,0)型代数成为有1模格的一个充分必要条件.这样大大简化了有1模格的等价定义.     

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.     

完备模格的有限条件

本文研究完备模格的有限条件,给出了完备模格是Artin(Noether)格的若干等价条件,得到了完备模格中元1分解为有限个独立原子并的等价刻画,证明了上连续完备半单模格中元1的任意两个独立原子分解具有相同的基数.     

正交模格OML上的同余关系

介绍了正交模格上同余关系的性质,给出正交模格上一个二元关系是同余关系的条件.证明了正交模格上的理想是正交模理想的充分必要条件扣等价命题,最后介绍了换位子理想.     

格中两类分配等式的关系研究

针对离散数学经典教材中提出的"交运算对并运算的分配等式和并运算对交运算的分配等式是等价的"这一结论,分析了一种常见的错误证明,通过一个反例说明该结论在一般的格中不一定成立,进一步证明这两个分配等式在且仅在模格中是等价的,并提出利用定义判断一个模格是否是分配格的简便算法.作为一个应用,重新证明了该教材中的一条定理.     

布尔矩阵的指标格的性质

介绍了布尔矩阵的行零元、列零元和相容子矩阵的定义并讨论了它们的性质,给出了布尔矩阵的指标格分别为分配格、半分配格和半模格的等价条件.     

格蕴涵代数的区间值(J)-模糊滤子理论

将区间值模糊集和D[0,1]上的t-模(J)应用于格蕴涵代数的滤子理论,引入格蕴涵代数的区间值,(J)-模糊(关联、正关联)滤子的概念,给出了它们的等价刻画,研究了它们之间的关系.     

关于完备格上的T-型矩阵方程

利用完备格L上的无限分配t-模T,研究了T-型矩阵方程A TX TB=C的解,得到该方程有解的一个等价条件。同时,在有解时给出求该方程整个解集的一个算法。     

连续格上的分析性质

在完备格中给出两个收敛性定义并且证明了这两个收敛性定义是等价的。把连续格和诱导拓扑与积拓扑的等价性建立了联系,并讨论了连续格上的拓扑性质。     

Hahn-Banach定理在V-凸性模定义中的应用

先给出了V-凸性模的两个等价定义,并利用Hahn-Banach定理给出了它们的等价性.其次,在V-凸性模定义的基础上引进了广义V-凸性模的概念,并给出了其两个等价定义.     

有1分配格的若干种等价定义

对有单位元1的分配格,给出若干种等价定义,并根据分配格所满足的幂等律、交换律、结合律、吸收律和分配律证明了最新定义与原始定义的等价性。     

The strong endomorphism kernel property for modular p-algebras and for distributive lattices

We study the strong endomorphism kernel property (SEKP) for some classes of universal algebras. Using the Katriňák-Mederly triple construction, we prove a universal equivalent condition under which a modular p-algebra has SEKP. As a consequence, we characterize distributive lattices with top element that enjoy SEKP. Using Priestley duality, we also characterize unbounded distributive lattices that have SEKP.     

Involutive Residuated Lattices Based on Modular and Distributive Lattices

An involutive residuated lattice (IRL) is a lattice-ordered monoid possessing residual operations and a dualizing element. We show that a large class of self-dual lattices may be endowed with an IRL structure, and give examples of lattices which fail to admit IRLs with natural algebraic conditions. A classification of all IRLs based on the modular lattices M _n is provided.     

Weakly Orthomodular and Dually Weakly Orthomodular Lattices

We introduce so-called weakly orthomodular and dually weakly orthomodular lattices which are lattices with a unary operation satisfying formally the orthomodular law or its dual although neither boundedness nor complementation is assumed. It turns out that lattices being both weakly orthomodular and dually weakly orthomodular are in fact complemented but the complementation need not be neither antitone nor an involution. Moreover, every modular lattice with complementation is both weakly orthomodular and dually weakly orthomodular. The class of weakly orthomodular lattices and the class of dually weakly orthomodular lattices form varieties which are arithmetical and congruence regular. Connections to left residuated lattices are presented and commuting elements are introduced. Using commuting elements, we define a center of such a (dually) weakly orthomodular lattice and we provide conditions under which such lattices can be represented as a non-trivial direct product.     

Two extension theorems. Modular functions on complemented lattices

We prove an extension theorem for modular functions on arbitrary lattices and an extension theorem for measures on orthomodular lattices. The first is used to obtain a representation of modular vector-valued functions defined on complemented lattices by measures on Boolean algebras. With the aid of this representation theorem we transfer control measure theorems, Vitali-Hahn-Saks and Nikodým theorems and the Liapunoff theorem about the range of measures to the setting of modular functions on complemented lattices.     

An Analogue of Distributivity for Ungraded Lattices

In this paper, we study lattices that posess both the properties of being extremal (in the sense of Markowsky) and of being left modular (in the sense of Blass and Sagan). We call such lattices trim and show that they posess some additional appealing properties, analogous to those of a distributive lattice. For example, trimness is preserved under taking intervals and suitable sublattices. Trim lattices satisfy a weakened form of modularity. The order complex of a trim lattice is contractible or homotopic to a sphere; the latter holds exactly if the maximum element of the lattice is a join of atoms. Any distributive lattice is trim, but trim lattices need not be graded. The main example of ungraded trim lattices are the Tamari lattices and generalizations of them. We show that the Cambrian lattices in types A and B defined by Reading are trim; we conjecture that all Cambrian lattices are trim.     

Varieties of Lattices with Geometric Descriptions

A lattice L is spatial if every element of L is a join of completely join-irreducible elements of L (points), and strongly spatial if it is spatial and the minimal coverings of completely join-irreducible elements are well-behaved. Herrmann et al. proved in 1994 that every modular lattice can be embedded, within its variety, into an algebraic and spatial lattice. We extend this result to n-distributive lattices, for fixed n. We deduce that the variety of all n-distributive lattices is generated by its finite members, thus it has a decidable word problem for free lattices. This solves two problems stated by Huhn in 1985. We prove that every modular (resp., n-distributive) lattice embeds within its variety into some strongly spatial lattice. Every lattice which is either algebraic modular spatial or bi-algebraic is strongly spatial. We also construct a lattice that cannot be embedded, within its variety, into any algebraic and spatial lattice. This lattice has a least and a largest element, and it generates a locally finite variety of join-semidistributive lattices.     

Modular functions: Uniform boundedness and compactness

We prove the Nikodym Boundedness, Brooks-Jewett and Vitali-Hahn-Saks theorems for modular functions on orthomodular lattices with SIP and on particular complemented or sectionally complemented lattices, and the equivalence, for any complemented or sectionally complemented lattice, between the Brooks-Jewett and Vitali-Hahn-Saks theorems for group-valued modular functions. As consequence, we obtain characterizations of relative, sequential and weak compactness in spaces of modular functions.