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1.
初基演算     
沈有鼎 《数学学报》1957,7(1):132-143
<正> 命题演算的构成,通常有三步骤的说法,即从 Johanson 的“极小演算”到 Heyting的构造论命题演算再到二值演算.此外,Lewis 从模态或严格蕴涵出发,也分别了许多步骤,以达到二值演算为其极限;特别值得注意的是最后三个步骤,即从 S4 到 S5 到二值演算.这两个三步骤就某意义说乃是通常命题演算的构成中最本质的步骤.综合这两个三步骤,会带来许多便利,而本文所提出的也就是作为二者共同基础的初基演算.  相似文献   

2.
陈吉象 《数学学报》1998,41(3):471-474
K.A.Hardie与K.H.Kamps研究过固定空间B上的迹同伦范畴([1]).他们引进了两对伴随函子PB┤NB与m┤m,此处m:AB是固定映射,PB:HBHB与m:HAHB是函子.我们在[2]中引进了分裂的范畴纤维化L:HbHB,并且证明了L┤J,J┤L.本文首先将PB┤NB推广到PBb┤NBb#,其中b:BB是任一固定映射,并且我们还得到涉及迹同伦范畴Hb与Hb的两对伴随函子,此处Hb是Hb的对偶.特别,Nb┤Pb不同于PB┤NB.  相似文献   

3.
两个分块矩阵相似性的研究   总被引:1,自引:1,他引:0  
给出两个分块矩阵相似的两个充分必要条件 .也就是说 ,如果两个方阵 A和 B在 A2 =0和 B2 =0的条件下 ,则两个分块矩阵 A C0 B 和 A 00 B 相似的充分必要条件是 :rank A C0 B =rank(A) +rank(B)和 AC +CB =0 .如果两个方阵 A和 B在 A2 =A和 B2 =B的条件下 ,则两个分块矩阵 A C0 B和 A 00 B 相似的充分必要条件是 :AC +CB =C.  相似文献   

4.
设X是维数大于2的Banach空间,映射δ:B(X)→B(X)是2-局部Lie三重导子,则对所有A∈B(X)有δ(A)=[A,T]+ψ(A),这里T∈B(X),ψ是从B(X)到FI的齐次映射且满足对所有A,B∈B(X)有ψ(A+B)=ψ(A),其中B是交换子的和.  相似文献   

5.
赵文正 《数学学报》2000,43(4):677-684
本文给出了DoiY.构造的偶交叉积BT■H的代数结构与ReshetikhimN.构造的双代数B■RH的余代数结构在张量空间B■H上构成双代数(记为Bτ■RH)的充要条件,利用此结论具体构造了一个有趣的例子B4■KZ2;证明了当B,H均为Hopf.代数时Bτ■RH也为Hopf代数,最后给出这类双代数的映射刻划。  相似文献   

6.
Let u be a harmonic map from a rotational symmetric manifold M and B a unit ball in M, let E(u|B) be the energy of the map u|B and E(u|∂B) the energy of the map u|∂B, then we obtain the relationship which is called the isoenergy inequality between E(u|B) and E(u|∂B):  相似文献   

7.
本文给出了算子方程AXB-X=C可解的若干充要条件,其中(A,B)为下列情形之一:A或B有闭值域;A(B*)有闭值域并且是单射或者相似于一个协亚正规算子并且B(A*)是单侧移位;A+(B(*+))幂有界,其值域R(A+) R(A)(R(B) R(B+)并且B(A*)是单侧移位;A=U*且B=U是Hardy空间上重数为1的单侧移位.而且,给出了解的表达式.  相似文献   

8.
Y.Q. Chen  K.P. Shum 《代数通讯》2013,41(9):3043-3055
Let A, B be rings and P a radical property. Call B an A-Algebra if B is an A-bimodule such that (ba)b1 = b(ab1), (bb1)a = b(b1a), a(bb1) = (ab)b1 for any a ∈ A and any b,b1 ∈ B. A ring R, written as R = A ? B, is called a quasi-direct sum of (A, B) if A is a subring of R, B is an ideal of R and R is a direct sum of A and B as additive groups. The following results are obtained: 1. A quasi-direct sum of (A, B) is uniquely determined by an A-Algebra B (up to isomorphism); 2. The P-radical of the Algebra B is the same as the P-radical of the ring B; 3. P(A ? B) = P(A) +(B) if and only if P(A)B + BP(A) ? P(B); 4. If B has an identity e then P(A ? B) = P(A)(1?e) + P(B); 5. If P(Z) = 0 for the integer ring Z, then P(Mn(R)) = Mn(P(R)) holds for all rings R if and only if the above equality holds for all unitary rings R. In addition, some relationships of radicals between rings (or algebras over a field, semigroup algebras, etc.) and their corresponding identity extensions are discussed.  相似文献   

9.
Let B be a domain ?? that supports nonconstant bounded analytic functions, let pe B. In [1] S.Fisher posed the question: Does the Ahlforsfunction for B and p map a maximal B onto the unit disc D? We give an example of a maximal B such that in B F(z) omits two values of D.  相似文献   

10.
Given a continuous seminorm p on a Hausdorff locally convex space X and nonempty subsets A, B of X, let Proximal(B;A) (resp. Prox(A,B)) denote the set of p-proximal points of B in A (resp. the set of ordered pairs of p-proximal points of the pair (A,B)). In this article we identify suitable families A,B of nonempty subsets of X and natural topologies on them with a view to study continuity properties of B →Proximal( B;A) and (A,B) →Prox(A,B). This leads us to obtain a best approximation result and a coincidence theorem for multifunctions defined on non-compact sets.  相似文献   

11.
设B,H是两个Hopf代数,构造了(ω,σ)-Smash积Bω#σH和(ν,α)-Smash余积Bν■αH,并给出了Bω#σH是Hopf代数和Bν■αH是双代数的充要条件,证明了许多已知的积和余积是它们的特殊情况.  相似文献   

12.
1 IntroductionRecently,various kinds of generalized convex functions were introduced.Bector andSingh[1 ] introduced a class of functions which called B-vex function.Bector,Suneja,andLalitha[2 ] introduced quasi B-vex function,pseudo B-vex function,B-invex function,quasi B-invex function,and pseudo B-invex function.We[3] extended invex function[4] ,gave thedefinitions of the symmetricη-function,symmetricη-pseudoconvex function,symmetricη-quasiconvex function for symmetric differentiable…  相似文献   

13.
One investigates estimates of the type ∥ABx∥?f(B)∥Ax∥, where A, B are matrices and x is a vector belonging to a certain subspace. One investigates the properties of the matrix seminorm f(B), in particular, its relation to the spectrum of the matrix B. For the case of a stochastic matrix B (which can be easily generalized to the case of a nonnegative matrix B) one derives estimates for f(B) which are convenient for practical computations (also on an electronic computer). One gives a numerical example illustrating the application of the results.  相似文献   

14.
李世群  何勇 《数学学报》2006,49(5):1189-119
设S为一个半群,B是S的一个双理想(即B是S的一个满足条件BSBB的子半群).如果对S的任意双理想C,D都有CDB蕴涵CB或DB,我们就称B为S的一个素双理想.如果K是一个N-覆盖的纯LR-带,我们就称K为一条拟链.本文证明了半群S的所有双理想都是素双理想的充分必要条件是S是一个幂等元形成拟链的纯整群并半群.  相似文献   

15.
In the last twenty years, a theory of real Jordan triples has been developed. In 1994 T. Dang and B. Russo introduced the concept of J*B–triple. These J*B–triples include real C*–algebras and complex JB*–triples. However, concerning J*B–triples, an important problem was left open. Indeed, the question was whether the complexification of a J*B–triple is a complex JB*–triple in some norm extending the original norm. T. Dang and B. Russo solved this problem for commutative J*B–triples. In this paper we characterize those J*B–triples with a unitary element whose complexifications are complex JB*–triples in some norm extending the original one. We actually find a necessary and sufficient new axiom to characterize those J*B–triples with a unitary element which are J*B–algebras in the sense of [1] or real JB*–triples in the sense of [4].  相似文献   

16.
By using the theory of the cone and partial ordering. It is studied that the existence and uniqueness of solutions for a non-monotone binary operator equation A(x, x)= x and operator system of equations A(x,x)=x,B(x,x)=x in Banach spaces. Where A and B can be decomposed A=A1+A2, B=B1+B2,A1 and B1 are mixed monotone, A2 and B2 are anti-mixed monotone. The results presented here improve and generalize some corresponding results of mixed monotone operator equations.  相似文献   

17.
银俊成  曹怀信 《应用数学》2012,25(2):357-362
本文给出C* -代数之间完全正映射的刻画,证明:如果A,B是有单位元的C*-代数,则映射Φ:A→B为完全正映射当且仅当存在保单位*-同态πA:A→B(K)、等距* -同态πB:B→B(H)及有界线性算子V:H→K,使得πB(Φ(1))=V*V 且■a∈A,都有πB(Φ(a))=V*π(a)V.作为推论,得到著名的Stinespring膨胀定理.  相似文献   

18.
基于值域的稠密性和闭性,有界线性算子的点谱可进一步细分为互不相交的四个组成部分,即四类点谱.设H_1,H_2,H_3为无穷维复可分Hilbert空间,记M_(D,E,F)=(A D E0 B F0 0 C)∈B(H_1H_2H_3).当对角算子A,B,C固定时,给出了M_(D,E,F)的四类点谱随D,E,F扰动的完全描述.  相似文献   

19.
本文给出了Doi Y.构造的偶交叉积B H的代数结构与Reshetikhim~N.构造的双代数BRH的余代数结构在张量空间B H上构成双代数(记为BRH)的充要条件,利用此结论具体构造了一个有趣的例子H4 KZ2,证明了当B,H均为Hopf.代数时BRH也为Hopf代数,最后给出这类双代数的映射刻划.  相似文献   

20.
The functional dimension of countable Hilbert spaces has been discussed by some authors. They showed that every countable Hilbert space with finite functional dimension is nuclear. In this paper the authors do further research on the functional dimension, and obtain the following results: (1) They construct a countable Hilbert space, which is nuclear, but its functional dimension is infinite. (2) The functional dimension of a Banach space is finite if and only if this space is finite dimensional. (3) Let B be a Banach space, B* be its dual, and denote the weak * topology of B* by σ(B*,B). Then the functional dimension of (B*,σ(B*,B)) is 1. By the third result, a class of topological linear spaces with finite functional dimension is presented.  相似文献   

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