共查询到20条相似文献,搜索用时 0 毫秒
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We give a new proof of Kiselman's minimum principle for plurisubharmonic functions, inspired by Demailly's regularization of plurisubharmonic functions by using Ohsawa–Takegoshi's extension theorem. 相似文献
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Klaus Dohmen 《Archiv der Mathematik》1999,72(4):298-303
We present an improvement of the inclusion-exclusion principle in which the number of terms is reduced by predicted cancellation. The improvement generalizes a related result of Narushima as well as a graph-theoretic theorem of Whitney. Applications concern chromatic polynomials of graphs and permanents of 0,1-matrices. 相似文献
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J Bárány 《Journal of Combinatorial Theory, Series A》1978,25(3):325-326
In the paper a short proof is given for Kneser's conjecture. The proof is based on Borsuk's theorem and on a theorem of Gale. 相似文献
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A Schrijver 《Journal of Combinatorial Theory, Series A》1978,25(1):80-83
A short proof is given of the following conjecture of Minc, proved in 1973 by Brègman. Let A be a n × n ? (0, 1)-matrix with ri ones in row i. Then per . 相似文献
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J. Goldstine 《Discrete Mathematics》1977,19(3):235-239
A strengthened form of the pumping lemma for context-free languages is used to give a simple proof of Parikh's Theorem. 相似文献
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Oliver Pretzel 《Discrete Mathematics》1979,25(1):91-92
Dilworth's famous theorem [1] states that if the maximal sized antichains of a finite poset X have n elements, then X can be covered by n chains. The number n is called the width of X. Apart from proofs relating the theorem to other key theorems of combinatorics (see [1–4]), there have been a number of direct proofs (see [1, 2, 5, 6]). The shortest of these is the one by Perles [5], the outline of which is as follows. 相似文献
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Meyniel's theorem states that a strict diconnected digraph has a directed Hamilton cycle if d(u) + d(v) ? 2n ? 1 for every pair u, v of nonadjacent vertices. We give short proof of this theorem. 相似文献
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D. S. Franzblau Doron Zeilberger 《Journal of Algorithms in Cognition, Informatics and Logic》1982,3(4):317-343
A well-known theorem of Frame, Robinson, and, Thrall states that if λ is a partition of n, then the number of Standard Young Tableaux of shape λ is n! divided by the product of the hook-lengths. We give a new combinatorial proof of this formula by exhibiting a bijection between the set of unsorted Young Tableaux of shape λ, and the set of pairs (T, S), where T is a Standard Young Tableau of shape λ and S is a “Pointer” Tableau of shape λ. 相似文献
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Recently, Naruse presented a beautiful cancellation-free hook-length formula for skew shapes. The formula involves a sum over objects called excited diagrams, and the term corresponding to each excited diagram has hook lengths in the denominator, like the classical hook-length formula due to Frame, Robinson and Thrall. In this paper, we present a simple bijection that proves an equivalent recursive version of Naruse’s result, in the same way that the celebrated hook-walk proof due to Greene, Nijenhuis and Wilf gives a bijective (or probabilistic) proof of the hook-length formula for ordinary shapes.In particular, we also give a new bijective proof of the classical hook-length formula, quite different from the known proofs. 相似文献
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Aaron D. Jaggard 《Random Structures and Algorithms》2007,31(2):247-250
Let 𝒫n be the set of all distinct ordered pairs (λ,λi), where λ is a partition of n and λi is a part size of λ. The primary result of this note is a combinatorial proof that the probability that, for a pair (λ,λi) chosen uniformly at random from 𝒫n, the multiplicity of λi in λ is 1 tends to 1/2 as n →∞. This is inspired by work of Corteel, Pittel, Savage, and Wilf (Random Structures and Algorithms 14 (1999), 185–197). © 2007 Wiley Periodicals, Inc. Random Struct. Alg., 2007 相似文献
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Aequationes mathematicae - We discuss Milne’s inequality and apply it to the sides of a convex quadrilateral to derive an approximation to the area of the quadrilateral via arithmetic and... 相似文献
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T.D Morley 《Journal of Mathematical Analysis and Applications》1979,70(1):33-41
In this paper we apply Maxwell's principle to give simple proofs of the properties of R: S, the parallel sum of two positive semi-definite linear operators. The parallel sum has been studied by Anderson, Ando, Duffin, Fillmore, Mitra, Williams, and others. In particular we give a short, elementary, and geometric proof of the result of Anderson and Duffin that gives the infimum of two orthogonal projections as twice their parallel sum. 相似文献