✦ LIBER ✦

A Semilattice on the Set of Permutations on an Infinite Set

✍ Scribed by I. G. Rosenberg

Publisher: John Wiley and Sons
Year: 1974
Tongue: English
Weight: 440 KB
Volume: 60
Category: Article
ISSN: 0025-584X
DOI: 10.1002/mana.19740600119

No coin nor oath required. For personal study only.

📜 SIMILAR VOLUMES

The Excedance Set of a Permutation

✍ Richard Ehrenborg; Einar Steingrı́msson 📂 Article 📅 2000 🏛 Elsevier Science 🌐 English ⚖ 124 KB

The excedance set of a permutation π = π 1 π 2 • • • π n is the set of indices i for which π i > i. We give a formula for the number of permutations with a given excedance set and recursive formulas satisfied by these numbers. We prove log-concavity of certain sequences of these numbers and we show

The Congruences on the Semigroup of Bala

The Congruences on the Semigroup of Balanced Transformations of an Infinite Set

✍ M.Paula O. Marques-Smith; R.P. Sullivan 📂 Article 📅 2000 🏛 Elsevier Science 🌐 English ⚖ 221 KB

showed that the semigroup generated by all non-identity idempotent transformations of an infinite set X is the disjoint union of two semigroups, one of which is denoted by H and consists of all balanced transformations of X (that is, all transformations whose defect, shift, and collapse are equal an

Note on large sets of infinite steiner s

Note on large sets of infinite steiner systems

✍ Peter J. Cameron 📂 Article 📅 1995 🏛 John Wiley and Sons 🌐 English ⚖ 250 KB 👁 1 views

Large sets of Steiner systems s ( t , k , n ) exist for all finite t and k with t < k and all infinite n. The vector space analogues exist over a field F for all finite t and k with f < R provided that either v or F is infinite, and n 1 2k -t + 1. This inequality is best possible. o 1995 John Wiley

On Infinite Sum-free Sets of Natural Num

On Infinite Sum-free Sets of Natural Numbers

✍ Tomasz łuczak; Tomasz Schoen 📂 Article 📅 1997 🏛 Elsevier Science 🌐 English ⚖ 346 KB

A subset of the natural numbers is k-sum-free if it contains no solutions of the equation x 1 + } } } +x k = y, and strongly k-sum-free when it is l-sum-free for every l=2, ..., k. It is shown that every k-sum-free set with upper density larger than 1Â(k+1) is a subset of a periodic k-sum-free set a

Set the Galaxy on Fire: An Anthology

✍ M. D. Cooper 📂 Fiction 📅 2016 🏛 The Wooden Pen Press 🌐 English ⚖ 63 KB 👁 3 views

**_This book is intended to be read after Destiny Lost and before New Canaan in the Orion War series_** The battle of Bollam's World is over, but war now looms over the Orion Arm of the galaxy. The arrival of the most powerful ship in human space is about to set the galaxy on fire. **Bollam’s War

On covering an independent set in a grid

On covering an independent set in a grid with a second independent set

✍ Rue, Rachel 📂 Article 📅 1996 🏛 John Wiley and Sons 🌐 English ⚖ 1011 KB

We show that for every independent set 0 in an n x m grid, n, m > 1, there is a second independent set X with the property that every member of 0 is adjacent to a t least one member of X. The proof gives a construction for X. Equivalently, we show that for every maximal independent set in a grid, th