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71.
In the paper, the notion of F function, i.e., a partial recursive function whose resemblance type consists of one isomorphism type, is generalized. 相似文献
72.
A nonempty and nonconstant partial recursive function such that any function resembling it is recursively isomorphic to it is called a t-function. It is proved that the domain of any t-function is neither a simple nor a pseudosimple set. 相似文献
73.
关于半直积的同构 总被引:4,自引:1,他引:3
刘修生 《武汉大学学报(理学版)》2003,49(3):293-296
设N,H是两个群,φ,ψ驴分别是从群H到N的自同构群Aut(N)的两个自同态,本文证明了当群H及同态映射φ,ψ满足一定条件下半直积与半直积同构的三个定理,而其中两个定理包括了已知的两个结果。 相似文献
74.
Every inverse semigroup possesses a natural partial order and therefore convexity with respect to this order is of interest.
We study the extent to which an inverse semigroup is determined by its lattice of convex inverse subsemigroups; that is, if
the lattices of two inverse semigroups are isomorphic, how are the semigroups related? We solve this problem completely for
semilattices and for inverse semigroups in general reduce it to the case where the lattice isomorphism induces an isomorphism
between the semilattices of idempotents of the semigroups. For many inverse semigroups, such as the monogenic ones, this case
is the only one that can occur. In Part II, a study of the reduced case enables us to prove that many inverse semigroups,
such as the free ones, are strictly determined by their lattices of convex inverse subsemigroups, and to show that the answer
obtained here for semilattices can be extended to a broad class of inverse semigroups, including all finite, aperiodic ones.
Received September 24, 2002; accepted in final form December 15, 2002. 相似文献
75.
N. S. Vinokurov 《Siberian Mathematical Journal》2006,47(5):835-843
We obtain exact estimates in the arithmetical and analytical hierarchies of index sets of various classes of automatic models. We also obtain estimates for the existence problems for computable isomorphism and embedding of automatic structures. 相似文献
76.
设{Ei:i∈I)是侧完备Riesz空间E中的一族理想,且Ei∩Ej=θ(i,j∈I,i≠j).文章引入理想族{Ei:i∈I)直和的概念,并给出一个表示定理.文章证明了:存在一个完备的正则Hausdorff空间X使得理想族的直和Riesz同构于C(X)其充要条件是对每个i∈I存在一个紧Hausdorff空间Xi使得Ei Riesz同构于C(X). 相似文献
77.
Edward Dobson 《Discrete Mathematics》2008,308(24):6047-6055
C.H. Li recently made the following conjecture: Let Γ be a circulant digraph of order n=n1n2 and degree m, where gcd(n1,n2)=1, n1 divides 4k, where k is odd and square-free, and every prime divisor of n2 is greater than m, or, if Γ is a circulant graph, every prime divisor of n2 is greater than 2m. Then Γ is a CI-digraph of Zn. In this paper we verify that this conjecture is true. 相似文献
78.
79.
Central simple Poisson algebras 总被引:1,自引:0,他引:1
SU Yucai & XU XiaopingDepartment of Mathematics Shanghai Jiaotong University Shanghai China Institute of Mathematics Academy of Mathematics System Sciences Chinese Academy of Sciences Beijing China 《中国科学A辑(英文版)》2004,47(2):245-263
Poisson algebras are fundamental algebraic structures in physics and sym-plectic geometry. However, the structure theory of Poisson algebras has not been well developed. In this paper, we determine the structure of the central simple Poisson algebras related to locally finite derivations, over an algebraically closed field of characteristic zero. The Lie algebra structures of these Poisson algebras are in general not finitely-graded. 相似文献
80.
We consider one class of matrix differential operators in the whole space. For this class of operators we establish the isomorphic properties in some special scales of weighted Sobolev spaces and study the regularity properties for solutions to the system of differential equations defined by these operators. The class of operators under consideration contains the stationary Navier–Stokes operator. 相似文献