An Extended Ockham Algebra with Endomorphism Kernel Property

An algebraic structure A is said to have the endomorphism kernel property if every congruence on A, other than the universal congruence, is the kernel of an endomorphism on A. In this paper, we consider the EKP （that is, endomorphism kernel property） for an extended Ockham algebra A. In particular, we describe the structure of the finite symmetric extended de Morgan algebras having EKP.     

同余可换的Stone代数

借助Stone代数的对偶空间的性质，考察了Stone代数的同余可换性.     

On symmetric extended MS-algebras whose congruences are permutable

Algebras whose congruences are permutable were investigated by a number of authors in the literature. In this paper, we study the symmetric extended MS-algebras whose congruences are permutable. Some results obtained by Jie Fang on symmetric extended De Morgan algebras are generalized.     

The Endomorphism Kernel Property in Finite Distributive Lattices and de Morgan Algebras

Abstract

An algebra 𝒜 has the endomorphism kernel property if every congruence on 𝒜 different from the universal congruence is the kernel of an endomorphism on 𝒜. We first consider this property when 𝒜 is a finite distributive lattice, and show that it holds if and only if 𝒜 is a cartesian product of chains. We then consider the case where 𝒜 is an Ockham algebra, and describe in particular the structure of the finite de Morgan algebras that have this property.     

德摩根代数上的拟一致和拟邻近

在［１］［２］［３］基础上，我们在德摩根代数上建立了拟一致和拟邻近两个新概念，并着重讨论了它们之间的关系。     

Free Algebras in Certain Varieties of Distributive Pseudocomplemented De Morgan Algebras

In this paper we characterize the join irreducible elements of the free algebras on n free generators in the subvarieties of the variety V₀ of pseudocomplemented De Morgan algebras satisfying the identity xx′* = (xx′*)′*.     

On a subvariety of semi-De Morgan algebras

A characterization of principal congruences of the subvariety C of semi-DeMorgan algebras is given. This characterization is applied to determine the subdirectly irreducible algebras of the variety C and to describe a poset such that the lattice of its order ideals is isomorphic to the lattice of subvarieties of C. This revised version was published online in June 2006 with corrections to the Cover Date.     

Semigroup Varieties on Whose Free Objects Almost All Fully Invariant Congruences are Weakly Permutable

A semigroup variety is said to be of index 2 if all nil-semigroups of the variety are semigroups with zero multiplication. We describe all semigroup varieties V of index 2 on free objects of which every two fully invariant congruences contained in the least semilattice congruence are weakly permutable, and semigroup varieties of index 2 all of whose subvarieties share the above-mentioned property.     

广义生灭最小Q过程的可配称性

研究全稳定广义生灭最小Q过程的可配称性,获得广义生灭最小Q过程是可配称的充分必要条件,以及最小Q过程是唯一的可配称Q过程的充分必要条件．     

Symmetric Brace Algebras

We develop a symmetric analog of brace algebras and discuss the relation of such algebras to L_∞-algebras. We give an alternate proof that the category of symmetric brace algebras is isomorphic to the category of pre-Lie algebras. As an application, symmetric braces are used to describe transfers of strongly homotopy structures. We then explain how these symmetric brace algebras may be used to examine the L_∞-algebras that result from a particular gauge theory for massless particles of high spin.Mathematics Subject Classifications (2000) 55S20 (primary), 70S15 (secondary).Tom Lada: The research of the first author was supported in part by NSF grant INT-0203119.Martin Markl: The research of the second author was supported by grant MŠMT ME 603 and by the Academy of Sciences of the Czech Republic, Institutional Research Plan No. AV0Z10190503.     

强De Morgan代数上的广义R0 t-模

在De Morgan代数上引入广义R0算子,举例说明了一般De Morgan代数中的广义R0算子不能构成t-模。引入强De Morgan代数的概念,讨论它的基本性质,证明强De Morgan代数L上的广义R0算子构成t-模(称为广义R0t-模)。给出若干重要反例,并证明强De Morgan代数上的广义R0t-模是左连续的。     

A subclass of Ockham algebras

Here we introduce a subclass of the class of Ockham algebras ( L ; f ) for which L satisfies the property that for every x ∈ L , there exists n ≥ 0 such that fn ( x ) and fn+1 ( x ) are complementary. We characterize the structure of the lattice of congruences on such an algebra ( L ; f ). We show that the lattice of compact congruences on L is a dual Stone lattice, and in particular, that the lattice Con L of congruences on L is boolean if and only if L is finite boolean. We also show that L is congruence coherent if and only if it is boolean. Finally, we give a sufficient and necessary condition to have the subdirectly irreducible chains.     

Jordan Algebras and Dual Affine Connections on Symmetric Cones

We study dually flat structures on symmetric cones associated with Jordan algebras. We give an interpretation of connections, a geometrical concept, in terms of Jordan algebras and show a relation between doubly autoparallel submanifolds and Jordan subalgebras.     

A Note on Semigroup Algebras of Permutable Semigroups

Let S be a semigroup and 𝔽 be a field. For an ideal J of the semigroup algebra 𝔽[S] of S over 𝔽, let ?_J denote the restriction (to S) of the congruence on 𝔽[S] defined by the ideal J. A semigroup S is called a permutable semigroup if α ○ β = β ○ α is satisfied for all congruences α and β of S. In this paper we show that if S is a semilattice or a rectangular band then φ_{{S; 𝔽}}: J → ?_J is a homomorphism of the semigroup (Con(𝔽[S]); ○ ) into the relation semigroup (?_S; ○ ) if and only if S is a permutable semigroup.     

模情况下对称代数在亚循环群作用下的周期性质

在本文中,我们考虑在亚循环群$G=C_p \times H$作用下将对称代数$\mathbb{F}[V]$分解为不可分解模的直和,其中$H$是一个$p^{\prime}$-模.当向量空间$V$作为$G$-模的不可分解直和部分对应的单$H$-模的规范多项式是它的对偶模的基底元素乘积的幂时, 我们证明了对称代数 $\mathbb{F}[V]$的周期性质.     

A Note on the Subdirectly Irreducible ckham Algebras

ＡＮｏｔｅｏｎｔｈｅＳｕｂｄｉｒｅｃｔｌｙＩｒｒｅｄｕｃｉｂｌｅｃｋｈａｍＡｌｇｅｂｒａｓ￥ＦａｎｇＪｉｅ（Ｄｅｐａｒｔｍｅｎｔｏｆｍａｔｈｅｍａｔｉｃｓ，ＺｈｏｎｇｓｈａｎＵｎｉｖｅｒｓｉｔｙ，Ｇｕａｎｇｚｈｏｕ，５１０２７５）Ａｂｓｔｒａｃｔ：Ｔ...     

Congruence relations on de Morgan algebras

Various classes of de Morgan algebras whose congruence relations satisfy special conditions are investigated together with their interrelationship. In particular, the classes of congruence permutable, congruence regular, and congruence uniform de Morgan algebras are studied.Presented by Joel Berman.     

具有Heyting结构的Ockham代数

引入一个具有Heyting结构Ockham代数,简称HO-代数．所谓HO-代数,是指具有（2,2,2,1,0,0）类型的代数（L;∧,∨,→,f,0,1）．其中（L;f）是Ockham代数,（L;→）是Heyting代数,且运算f和→由恒等式f（x→y）=f^2（x）∧f（y）与f（x）→y=f^2（x）∨y所连结．主要讨论了HO-代数的同余关系的性质．并刻画了其次直不可约代数的某些性质．