Fuzzy蕴涵代数

本文讨论一个新的代数系统Fuzzy蕴涵代数,简称FI代数。FI代数是[0,1]值逻辑的蕴涵连接词的代数抽象,我们讨论了两类重要的FI代数—正则FI代数和HFI代数,并指出正则HFI代数与Boole代数的内在联系。     

相对假补格上的量词运算

如所周知,Boole代数可看作对古典二值命题演算进行抽象所得代数系统。作为古典一目谓词演算及古典狭谓词演算的代数抽象则有一元Boole代数及多元Boole代数的理论。后者已由Halmos在一系列题为《代数逻辑》的论文中加以发展。对于各种非古典演算,建立相应的抽象代数理论也是可能的。Tarski和McKinsey等已对某些著名的非古典命题演算进行了此类研究,并由之解决了相应演算的语义完全性问题。例如,对于Heyting的直觉主义演算,相应的代数为Brouwer代数或其对偶──     

Boole算子Fuzzy逻辑

将算子Fuzzy逻辑建立在Boole代数上,从而提出了Boole算子Fuzzy逻辑(简称BOFL),并且在BOFL中引进了λ-归结推理方法,BOFL系统可以用于模糊知识的定性描述,并且BOFL更自然地将经典逻辑作为它的特例。     

基于完备IMTL代数的L模糊粗糙集

IMTL代数是一类重要的非经典逻辑代数,基于IMTL代数的L模糊粗糙集可以刻画信息系统中具有不完备性、模糊性与不可比较性的信息.本文讨论了基于完备IMTL代数的L模糊粗糙集的表示定理,还讨论了此种L模糊粗糙集的上下近似算子的性质以及近似算子的公理化定义方法.     

分配的Fuzzy蕴涵代数

给出了分配的Fuzzy蕴涵代数的定义并探讨了其有关性质，接着本文证明了分配的Fuzzy蕴涵代数与Boole代数、正则的HFI代数是相互等价的，从而得到Boole代数的两个等价形式，并且证明了分配的Fuzzy蕴涵代数是BL代数，最后得到了FI代数成为Boole代数的几个充要条件。     

伪BCI-代数的导出半群与T-部分（英文）

伪BCI-代数是一类非经典逻辑代数,它是伪BCK-代数的推广,而伪BCK-代数与各种非可换模糊逻辑代数有密切关系。本文从任意伪BCI-代数出发,构造了两种加法运算,进而得到两个导出半群。同时,本文引入强伪BCI-代数、伪BCI-代数的T-部分等概念,给出伪BCI-代数的T-部分成为伪BCI-滤子的一些等价条件。     

认知本体论视角下因素空间的性质与对偶空间

因素空间是论域U和因素族F的偶对(U,F),其中F是一个Boole代数。针对因素空间定义中逻辑运算符"∧"和"∨"的意义同Boole代数的经典描述相悖的问题展开讨论,将运算符"∧"和"∨"的意义回归Boole代数的经典用法,从认知本体论的视角讨论因素空间的性质。关于因素的认知能力,发现因素空间的定义显化了解析力、隐化了概括力,因素的解析力主导了因素空间的性质。在这一发现的基础上,利用因素的概括力和解析力的反变关系,采用隐化解析力、显化概括力的数学技术,发现了对偶因素空间。结果表明,无论由因素的概括力还是解析力主导因素空间性质的讨论,因素族F都是一个Boole代数。     

基于完备剩余格值逻辑的BCI-代数的三种模糊理想

通过完备剩余格值逻辑中一元模糊谓词，将经典BCI-代数中的p-理想、q-理想和a-理想进行重新刻画，引入了BCI-代数的l-值模糊p-理想、l-值模糊q-理想和l-值模糊a-理想的概念。利用完备剩余格值逻辑的语义方法，研究这三种l-值模糊理想的性质及关系，推广了经典模糊情形下相应的现有结论。     

DR0代数:由De Morgan代数导出的正则剩余格

首先讨论了De Morgan代数与剩余格的关系，并引入强De Morgan代数的概念，讨论了它的基本性质．随后，将著名的R0蕴涵拓广到De Morgan代数上，称为广义R0蕴涵；证明了添加广义凰蕴涵和相应 算子后的De Morgan代数L成为剩余格的充要条件是L为强De Morgan代数，并由此引入D‰代数的概念．接着，研究了DR0代数与‰代数的关系，证明了以下结论：Boole代数是DR0代数；全序DR0代数和全序R0代数等价；DR0代数是R0代数当且仅当它满足预线性条件；无中点的DR0代数是BL代数当且仅当它是Boole代数．最后，举例说明了非D兄D代数的RD代数、以及非R0代数的DR0代数都是存在的．     

MTL-代数上的广义赋值

本文研究了MTL-代数上的几类广义赋值,讨论了MTL-代数上广义赋值、态以及滤子之间的关系,获得了MTL-代数上广义赋值成为(正)关联广义赋值的等价刻画,并基于广义赋值构造的同余关系研究了MTL-代数的商结构.所得结果推广了基于三角模的模糊逻辑代数上广义赋值的相关理论,进一步丰富了基于三角模的模糊逻辑代数上概率测度的代数结论.     

Nijenhuis algebras, NS algebras, and N-dendriform algebras

In this paper, we study (associative) Nijenhuis algebras, with emphasis on the relationship between the category of Nijenhuis algebras and the categories of NS algebras and related algebras. This is in analogy to the well-known theory of the adjoint functor from the category of Lie algebras to that of associative algebras, and the more recent results on the adjoint functor from the categories of dendriform and tridendriform algebras to that of Rota-Baxter algebras. We first give an explicit construction of free Nijenhuis algebras and then apply it to obtain the universal enveloping Nijenhuis algebra of an NS algebra. We further apply the construction to determine the binary quadratic nonsymmetric algebra, called the N-dendriform algebra, that is compatible with the Nijenhuis algebra. As it turns out, the N-dendriform algebra has more relations than the NS algebra.     

The Natural Quiver of an Artinian Algebra

The motivation of this paper is to study the natural quiver of an artinian algebra, a new kind of quivers, as a tool independing upon the associated basic algebra. In Li (J Aust Math Soc 83:385–416, 2007), the notion of the natural quiver of an artinian algebra was introduced and then was used to generalize the Gabriel theorem for non-basic artinian algebras splitting over radicals and non-basic finite dimensional algebras with 2-nilpotent radicals via pseudo path algebras and generalized path algebras respectively. In this paper, firstly we consider the relationship between the natural quiver and the ordinary quiver of a finite dimensional algebra. Secondly, the generalized Gabriel theorem is obtained for radical-graded artinian algebras. Moreover, Gabriel-type algebras are introduced to outline those artinian algebras satisfying the generalized Gabriel theorem here and in Li (J Aust Math Soc 83:385–416, 2007). For such algebras, the uniqueness of the related generalized path algebra and quiver holds up to isomorphism in the case when the ideal is admissible. For an artinian algebra, there are two basic algebras, the first is that associated to the algebra itself; the second is that associated to the correspondent generalized path algebra. In the final part, it is shown that for a Gabriel-type artinian algebra, the first basic algebra is a quotient of the second basic algebra. In the end, we give an example of a skew group algebra in which the relation between the natural quiver and the ordinary quiver is discussed.     

Toroidal李代数上的Poisson代数结构

非交换的Poisson代数同时具有结合代数和李代数两种代数结构,而结合代数和李代数之间满足所谓的Leibniz法则．文中确定了Toroidal李代数上所有的Poisson代数结构,推广了仿射Kac-Moody代数上相应的结论．     

Initial Chain Algebras on Pseudotrees

We investigate a new class of Boolean algebra, called initial chain algebras on pseudotrees. We discuss the relationship between this class and other classes of Boolean algebras. Every interval algebra, and hence every countable Boolean algebra, is an initial chain algebra. Every initial chain algebra on a tree is a superatomic Boolean algebra, and every initial chain algebra on a pseudotree is a minimally-generated Boolean algebra.We show that a free product of two infinite Boolean algebras is an initial chain algebra if and only if both factors are countable.     

李代数W(2,2)上的Hom-李代数结构

李代数W（2，2）是一类重要的无限维李代数，它是在研究权为2的向量生成的顶点算子代数的过程当中提出来的.Hom-李代数是指同时具备代数结构和李代数结构的一类代数，并且乘法与李代数乘法运算满足Leibniz法则.本文确定了李代数W（2，2）上的Hom-李代数结构.主要结论是李代数W（2，2）上没有非平凡的Hom-李代数结构.本文的研究结果对于W（2，2）代数的进一步研究有一定的帮助作用.     

A representation of weak effect algebras

Weak effect algebras were introduced by the author as a generalization of effect algebras and pseudoeffect algebras. It was shown that having a basic algebra, we can restrict its binary operation to orthogonal elements only and what we get is just a weak effect algebra. However, the converse construction is impossible due to the fact that the underlying poset of a basic algebra is a lattice which need not be true for weak effect algebras. Hence, we found a weaker structure than a basic algebra which can serve as a representation of a weak effect algebra.     

Projective algebras and primitive subquasivarieties in varieties with factor congruences

We prove that in the varieties where every compact congruence is a factor congruence and every nontrivial algebra contains a minimal subalgebra, a finitely presented algebra is projective if and only if it has every minimal algebra as its homomorphic image. Using this criterion of projectivity, we describe the primitive subquasivarieties of discriminator varieties that have a finite minimal algebra embedded in every nontrivial algebra from this variety. In particular, we describe the primitive quasivarieties of discriminator varieties of monadic Heyting algebras, Heyting algebras with regular involution, Heyting algebras with a dual pseudocomplement, and double-Heyting algebras.     

The pasting constructions for effect algebras

The aim of this paper is to present several techniques of constructing a lattice-ordered effect algebra from a given family of lattice-ordered effect algebras, and to study the structure of finite lattice-ordered effect algebras. Firstly, we prove that any finite MV-effect algebra can be obtained by substituting the atoms of some Boolean algebra by linear MV-effect algebras. Then some conditions which can guarantee that the pasting of a family of effect algebras is an effect algebra are provided. At last, we prove that any finite lattice-ordered effect algebra E without atoms of type 2 can be obtained by substituting the atoms of some orthomodular lattice by linear MV-effect algebras. Furthermore, we give a way how to paste a lattice-ordered effect algebra from the family of MV-effect algebras.     

Coset relation algebras

A measurable relation algebra is a relation algebra in which the identity element is a sum of atoms that can be measured in the sense that the “size” of each such atom can be defined in an intuitive and reasonable way (within the framework of the first-order theory of relation algebras). A large class of examples of such algebras, using systems of groups and coordinated systems of isomorphisms between quotients of the groups, has been constructed. This class of group relation algebras is not large enough to exhaust the class of all measurable relation algebras. In the present article, the class of examples of measurable relation algebras is considerably extended by adding one more ingredient to the mix: systems of cosets that are used to “shift” the operation of relative multiplication. It is shown that, under certain additional hypotheses on the system of cosets, each such coset relation algebra with a shifted operation of relative multiplication is an example of a measurable relation algebra. We also show that the class of coset relation algebras does contain examples that are not representable as set relation algebras. In later articles, it is shown that the class of coset relation algebras is adequate to the task of describing all measurable relation algebras in the sense that every atomic measurable relation algebra is essentially isomorphic to a coset relation algebra, and the class of group relation algebras is similarly adequate to the task of representing all measurable relation algebras in which the associated groups are finite and cyclic.     

Left-symmetric algebras of derivations of free algebras

A structure of a left-symmetric algebra on the set of all derivations of a free algebra is introduced such that its commutator algebra becomes the usual Lie algebra of derivations. Left and right nilpotent elements of left-symmetric algebras of derivations are studied. Simple left-symmetric algebras of derivations and Novikov algebras of derivations are described. It is also proved that the positive part of the left-symmetric algebra of derivations of a free nonassociative symmetric m-ary algebra in one free variable is generated by one derivation and some right nilpotent derivations are described.