有限生成自由代数FV（LK）（n）的自同构群（英文）

本文研究了自同构群AutLk和AutFV(LK)(n)的结构问题.利用了正交模格及其自同构群的直积分解方法,获得了正交模格Lk和自由代数FV(LK)(n)的自同构群的直积分解式.     

AUTOMORPHISM GROUP OF FINITELY GENERATED FREE ALGEBRAS FV(Lκ)(n)

本文研究了自同构群AutLκ和AutFV(LK)(n)的结构问题.利用了正交模格及其自同构群的直积分解方法,获得了正交模格Lκ和自由代数FV(LK)(n)的自同构群的直积分解式.     

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.     

不可分的正定幺模Hermite型的构作

本文给出了构作Z[m^1/2i]上不可分的正定幺模n秩Hermite格当m?3(mod4)时的方法.对任何自然数n,除了n=2,3,4,5(n=2,3)的例外情形,证明了存在Gauss整环Z[i](整环Z[2^1/2i])上不可分的正定幺模n秩正规Hermi-te格并给出它们的明显结构.又对任何n=4k(n=2k)构作了Z[i][(Z2^1/2i])上不可分的正定幺模n秩偶Hermite格.     

实二次域上正定偶幺模格的类群

本文综合利用邻格方法及Siegel mass公式证明了实二次域Q（√d)上∨≌In(n≥4)内的偶幺模格类数为2当且仅当Q（√3）,n=4及Q（√5），n=8。     

Z[(1 21~(1/2))/2]上正定幺模格的分类(英文)

本文综合利用邻格方法及Siegelmass公式对Z[(1 2 1) /2 ]上秩 4的正定幺模格实现了分类 ,得到了gen(I4 )的类数为 9,偶模格的类数为 3,并且给了代表格     

实二次域上正定偶幺模格的类数

本文综合利用邻格方法及Siegel　mass公式证明了实二次域Q( )上 内的偶幺模 格类数为2当且仅当Q( ),n=4及Q( ).n=8.     

格序模的f—复盖

J.Martinez首先利用同调的方法研究了格序结构,讨论了偏序模的张量积.W.Powell和A.Bigard分别在1981年和1973年研究了格序模的自由对象,描述了自由f—模的结构.作者推广并且改进了他们的工作,讨论了格序模的f—张量积.本文讨论格序模的f—模复盖,给出复盖函子,f—张量积函子和嵌入函子的关系.     

Z[(1+√21)/2]上正定幺模格的分类

本文利用邻 方法及Ｓｉｅｇｅｌ ｍａｓｓ公式对Ｚ「１＋√２１／２」上秩４的正定幺模格实现了分类,得到了ｇｅｎ（Ｉ４）的类数为９,偶模格的类数为３,并且给了代表格。     

全实代数数域上正定幺模格的分类

本文推广了邻格方法,并利用局部格,正旋量种及种的分类理论,给出了维数4判别式1的二次空间上幺模种的个数公式,正定幺模格种的质量与邻格数的关系公式,以及幺模格种的邻格图,正定幺模格种质量的计算方法.还完成了判别式148的全实三次循环代数数域K_(148)上二次空间V≌〈1〉⊥〈1〉⊥〈1〉⊥〈1〉内的所有5个正定幺模格种的分类.     

Epimorphisms in Certain Varieties of Algebras

We prove a lemma which, under restrictive conditions, shows that epimorphisms in V are surjective if this is true for epimorphisms from irreducible members of V. This lemma is applied to varieties of orthomodular lattices which are generated by orthomodular lattices of bounded height, and to varieties of orthomodular lattices which are generated by orthomodular lattices which are the horizontal sum of their blocks. The lemma can also be applied to obtain known results for discriminator varieties.     

Amalgamation of Ortholattices

We show that the variety of ortholattices has the strong amalgamation property and that the variety of orthomodular lattices has the strong Boolean amalgamation property, i.e. that two orthomodular lattices can be strongly amalgamated over a common Boolean subalgebra. We give examples to show that the variety orthomodular lattices does not have the amalgamation property and that the variety of modular ortholattices does not even have the Boolean amalgamation property. We further show that no non-Boolean variety of orthomodular lattices which is generated by orthomodular lattices of bounded height can have the Boolean amalgamation property.     

The free orthomodular lattice on countably many generators is a subalgebra of the free orthomodular lattice on three generators

We show every at most countable orthomodular lattice is a subalgebra of one generated by three elements. As a corollary we obtain that the free orthomodular lattice on countably many generators is a subalgebra of the free orthomodular lattice on three generators. This answers a question raised by Bruns in 1976 [2] and listed as Problem 15 in Kalmbach's book on orthomodular lattices [6]. Received April 12, 2001; accepted in final form May 6, 2002.     

Embeddings into Orthomodular Lattices with Given Centers,State Spaces and Automorphism Groups

We prove that, given a nontrivial Boolean algebra B, a compact convex set S and a group G, there is an orthomodular lattice L with the center isomorphic to B, the automorphism group isomorphic to G, and the state space affinely homeomorphic to S. Moreover, given an orthomodular lattice J admitting at least one state, L can be chosen such that J is its subalgebra.     

Compact orthoalgebras

We initiate a study of topological orthoalgebras (TOAs), concentrating on the compact case. Examples of TOAs include topological orthomodular lattices, and also the projection lattice of a Hilbert space. As the latter example illustrates, a lattice-ordered TOA need not be a topological lattice. However, we show that a compact Boolean TOA is a topological Boolean algebra. Using this, we prove that any compact regular TOA is atomistic , and has a compact center. We prove also that any compact TOA with isolated is of finite height. We then focus on stably ordered TOAs: those in which the upper set generated by an open set is open. These include both topological orthomodular lattices and interval orthoalgebras - in particular, projection lattices. We show that the topology of a compact stably-ordered TOA with isolated is determined by that of its space of atoms.

     

Quasivarieties of orthomodular lattices determined by conditions on states

In this paper we carry on the research initiated in [13] and [14]. We consider classes of orthomodular lattices which satisfy certain state and polynomial conditions. We show that these classes form quasivarieties. We then exhibit basic examples of these quasivarieties (some of these examples originated in the quantum logic theory). We finally show how the quasivarieties in question can be described in terms of implicative equations. (It should be noted that in some cases we have not been able to clarify whether or not a class shown to be a quasivariety is a variety, see Section 2.) Received May 26, 1998; accepted in final form May 19, 1999.     

Orthomodular lattices with state-separated noncompatible pairs

In the logico-algebraic foundation of quantum mechanics one often deals with the orthomodular lattices (OML) which enjoy state-separating properties of noncompatible pairs (see e.g. [18], [9] and [15]). These properties usually guarantee reasonable richness of the state space—an assumption needed in developing the theory of quantum logics. In this note we consider these classes of OMLs from the universal algebra standpoint, showing, as the main result, that these classes form quasivarieties. We also illustrate by examples that these classes may (and need not) be varieties. The results supplement the research carried on in [1], [3], [4], [5], [6], [11], [12], [13] and [16].     

Kripke‐style Semantics of Orthomodular Logics

We present here a Kripke‐style semantics for propositional orthomodular logics that is based on the representation theorem for orthomodular lattices by D.J. Foulis ([2]), in which a sort of semigroups is employed. This semantics can characterize the logics above the orthomodular logic by some elementary conditions.     

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.