Kleene代数的诱导子代数及理想

由于逻辑学研究的需要 ,Kleene代数理论的重要性已越来越明显 .本文主要研究了Kleene代数的子代数及理想的一些性质 ,得到了一些比较好的结果 .     

伪i-内射半模

主要引进了伪i-内射半模的定义,并根据对偶原则,参照k-投射半模及内射模的结论,得到了伪i-内射半模的一些很好的性质,从而实现了把环中内射模的某屿性质在半环中内射半模方面的部分推广.     

R_0-代数[0,1]的子代数与广义重言式

本文是对修正的Kleene系统中广义重言式理论的推广,讨论了R_0-代数[0,1]的各类无限子R_0-代数中的广义重言式,证明了在子R_0-代数E_2中,中存在着可数多个不同的广义重言式。     

π-模余代数与π-模余理想

主要讨论局部有限维的Hopfπ-代数H上π-模余代数与π-模余理想.给出了π-H-模余代数与π-H~*-余模代数之间的对偶关系,得到了π-H-模余理想的一个充分必要条件.     

Ni-内射半模及其性质

主要引进了Ni-内射半模的概念,并结合环中N-内射模与半环中内射半模的性质,得到了关于Ni-内射半模的一些性质,这些性质是内射模与内射半模性质的推广.     

基于左连续伪T-模的非可换模糊逻辑系统PUL*

对P．Hájek建立的模糊逻辑系统psMTL进行了扩充,基于一般左连续伪T-模提出了非可换模糊逻辑系统PUL~*,证明了它的可靠性定理．同时,以PUL~*系统的Lindenbaum代数结构为背景引入PUL~*-代数概念,建立了相应的滤子理论,得到PUL~*-代数的正规素滤子定理,借此证明了PUL~*系统的完备性．     

自反算子代数的双边模(Ⅱ)

本文对自反算子代数的σ-弱闭双边模的结构以及Von Neumann代数的NEST子代数的模交换子进行了研究。首先给出了自反算子代数的σ-弱闭双边模的一个不变量,并由此而证明了双边模的一种具体而又简洁的表示定理。对于某些特殊的Von Neumann 代数的NEST子代数的双边模,证明了模交换子的一些结果,这些结果包含了[2]中相应的定理。     

弱拟Hopf代数上的积分理论

本文主要讨论弱拟Hopf代数上的积分理论.首先将Hopf模基本结构定理推 广到弱拟Hopf代数上,并在给出积分与余积分的概念后,考虑了有限维弱拟Hopf代 数的对称性及半单性.     

群逆伪BCI-代数与群逆滤子(英文)

伪BCK-代数是非可换模糊逻辑(蕴涵片段)的基本代数框架,伪BCI-代数是伪BCK-代数的推广,本文研究伪BCI-代数的结构。首先,借助BZ-代数(又称弱BCC-代数)给出伪BCI-代数的一个特征性质;其次,通过引入群逆伪BCI-代数的概念,研究了伪BCI-代数与(非可换)群之间的关系;接着,引入群逆滤子、优滤子和正规滤子的概念,并通过它们给出伪BCI-代数成为群逆伪BCI-代数(以及滤子成为p-滤子)的充要条件;最后,证明了如下结论:(1)平均伪BCI-代数等价于p-半单BCI-代数;(2)伪BCI-代数的每一个滤子是p-滤子,当且仅当它是群逆的且其伴随群的每一个子群是正规子群。     

双重半伪补MS代数的滤子同余关系

在双重半伪补MS代数上引入余核滤子的概念,构造了余核滤子同余关系表达式,获得了余核滤子判别定理.根据双重半伪补MS代数的运算特征及主同余表示理论,获得了余核滤子同余关系的若干等价表达式并证明了双重半伪补MS代数余核滤子与其同余关系是同构的.所得结论为Ockham代数类余核滤子性质的研究提供了方法,丰富了序代数结构理论.     

对偶半模与自反半模

本文在半模范畴中建立了对偶半模与自反半模的概念，并把模范畴中有关模的对偶性与自反性的结果完整地推广到半模范畴中。     

Affine completeness of Kleene algebras

An algebra is called affine complete if all its compatible (i.e. congruence-preserving) functions are polynomial functions. In this paper we characterize affine complete members in the variety of Kleene algebras. We also characterize local polynomial functions of Kleene algebras and use this result to describe locally affine complete Kleene algebras. Received December 20, 1996; accepted in final form March 24, 1997.     

On Flat Semimodules over Semirings

The following analog of the characterization of flat modules has been obtained for the variety of semimodules over a semiring R: A semimodule _RA is flat (i.e., the tensor product functor – A preserves all finite limits) iff A is L-flat (i.e., A is a filtered colimit of finitely generated free semimodules). We also give new (homological) characterizations of Boolean algebras and complete Boolean algebras within the classes of distributive lattices and Boolean algebras, respectively, which solve two problems left open in [14]. It is also shown that, in contrast with the case of modules over rings, in general for semimodules over semirings the notions of flatness and mono-.atness (i.e., the tensor product functor – A preserves monomorphisms) are different.     

Crossed Semimodules and Schreier Internal Categories in the Category of Monoids

We introduce the notion of a Schreier internal category in the category of monoids and prove that the category of Schreier internal categories in the category of monoids is equivalent to the category of crossed semimodules. This extends a well-known equivalence of categories between the category of internal categories in the category of groups and the category of crossed modules.     

Some homological characterizations of semigroups and semirings

In this paper we characterize semirings all of whose p-injective semimodules are injective. We also classify monoids all of whose p-injective acts are injective.     

Hopf Categories

We introduce Hopf categories enriched over braided monoidal categories. The notion is linked to several recently developed notions in Hopf algebra theory, such as Hopf group (co)algebras, weak Hopf algebras and duoidal categories. We generalize the fundamental theorem for Hopf modules and some of its applications to Hopf categories.     

Local Density of Kleene Degrees

Concerning Post's problem for Kleene degrees and its relativization, Hrbacek showed in [1] and [2] that if V = L, then Kleene degrees of coanalytic sets are dense, and then for all K ?^ωω, there are N₁ sets which are Kleene semirecursive in K and not Kleene recursive in each other and K. But the density of Kleene semirecursive in K Kleene degrees is not obtained from these theorems. In this note, we extend these theorems by showing that if V = L, then for all K ? ^ωω, Kleene semirecursive in K Kleene degrees are dense above K.     

拟主k-投射半模(英文)

In this paper,we principally introduce the concept of quasiprincipally k-projective semimodules,on the basis of the theories of k-projective semimodules and quasi-principally modules,we get some good properties of quasi-principally k-projective semimodules,therefore generalize some properties of quasi-principally modules of ring and k-projective semimodules of semiring to quasi-principally k-projective semimodules of semiring.