pigeonhole principle


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pigeonhole principle

[′pij·ən‚hōl ‚prin·sə·pəl]
(mathematics)
The principle, that if a very large set of elements is partitioned into a small number of blocks, then at least one block contains a rather large number of elements. Also known as Dirichlet drawer principle.
References in periodicals archive ?
This book supplies students with 112 introductory to intermediate combinatorial problems drawn from the AwesomeMath summer program, as well as tools for solving counting problems, proof techniques, and examples related counting basics, permutations and combinations, multinomials, the principle of inclusion-exclusion, Pascal's triangle and the binomial theorem, the double counting principle, the pigeonhole principle, induction, recurrence relations, graph theory, invariants, combinatorial geometry, generating functions, and probabilities and probabilistic method.
Then it follows by the pigeonhole principle that there is one vertex of H with degree at least n - 2 and another vertex of H of degree at least n - 3.
3]) = 10, it follows by the pigeonhole principle that at least one vertex in [V.
3]) = 10, it follows by the pigeonhole principle that at least two vertices in Vi have degree at least 3.
Since [delta](H) [greater than or equal to] 2, it follows by the pigeonhole principle that at least two vertices in [V.
The topics include the multiplication principle, the distribution of balls into boxes, the binomial expansion, the principles of inclusion and exclusion, the pigeonhole principle, and the Catalan numbers.
They begin with a few examples, just to let students get a feel for it, then look at fundamentals of enumeration; the pigeonhole principle and Ramsey's theorem; the principle of inclusion and exclusion; generating functions and recurrence relations; Catalan, Bell, and Stirling numbers; symmetries and the Polya-Redfield method; graph theory; coding theory; Latin squares; balanced incomplete block designs; and linear algebra methods in combinatorics.
We show that in the classical examples of the Pigeonhole Principle, Tseitin graph tautologies, and random k-CNF's, these expansion properties are quite simple to prove (indeed, they comprised in some implicit way the simple part of the existing lower bound proofs).
The topics are basic counting methods, generating functions, the pigeonhole principle, Ramsey theory, error-correcting codes, and combinatorial designs.
2] + 1 vertices in S, by the pigeonhole principle, without loss of generality, there are at least 2k + 1 vertices in S [intersection] [?
They explain such topics as combinatorics is, permutations and combinations, the inclusion-exclusion principle, generating functions and recurrence relations, trees, group actions, and Dirichlet's pigeonhole principle.
The book's ten chapters cover induction, combinatorics, the whole numbers, geometric transformations, and inequalities, in addition to graphs, the pigeonhole principle, complex numbers and polynomials, rational approximations and mathematics at the computer.