Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
The Bounds for the Number of Linear Extensions Via Chain and Antichain Coverings. / Bochkov, I. A.; Petrov, F. V.
в: Order, 22.10.2020.Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
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TY - JOUR
T1 - The Bounds for the Number of Linear Extensions Via Chain and Antichain Coverings
AU - Bochkov, I. A.
AU - Petrov, F. V.
N1 - Funding Information: The work was supported by the Foundation for the Advancement of Theoretical Physics and Mathematics “BASIS”. Publisher Copyright: © 2020, Springer Nature B.V. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/10/22
Y1 - 2020/10/22
N2 - Let (P, ≤) be a finite poset. Define the numbers a1,a2,… (respectively, c1,c2,…) so that a1 + … + ak (respectively, c1 + … + ck) is the maximal number of elements of P which may be covered by k antichains (respectively, k chains.) Then the number e(P) of linear extensions of poset P is not less than ∏ ai! and not more than n! / ∏ ci!. A corollary: if P is partitioned onto disjoint antichains of sizes b1,b2,…, then e(P) ≥ ∏ bi!.
AB - Let (P, ≤) be a finite poset. Define the numbers a1,a2,… (respectively, c1,c2,…) so that a1 + … + ak (respectively, c1 + … + ck) is the maximal number of elements of P which may be covered by k antichains (respectively, k chains.) Then the number e(P) of linear extensions of poset P is not less than ∏ ai! and not more than n! / ∏ ci!. A corollary: if P is partitioned onto disjoint antichains of sizes b1,b2,…, then e(P) ≥ ∏ bi!.
KW - Antichains covering
KW - Chains covering
KW - Linear extension
UR - http://www.scopus.com/inward/record.url?scp=85092900227&partnerID=8YFLogxK
U2 - 10.1007/s11083-020-09542-3
DO - 10.1007/s11083-020-09542-3
M3 - Article
AN - SCOPUS:85092900227
JO - Order
JF - Order
SN - 0167-8094
ER -
ID: 75247476