Forbidden subgraphs in terms of forbidden quantifiers.

نویسندگان

چکیده

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Forbidden Subgraphs and Pancyclicity

We prove that every 2{connected K 1;3-free and Z 3 ?free graph is hamiltonian except for two graphs. Furthermore, we give a complete characterization of all 2?connected, K 1;3-free graphs, which are not pancyclic, and which are Z 3-free, B-free, W-free, or HP 7 ?free.

متن کامل

Graphs with Forbidden Subgraphs

Many graphs which are encountered in the study of graph theory are characterized by a type of configuration or subgraph they possess. However, there are occasions when such graphs are more easily defined or described by the kind of subgraphs they are not permitted to contain. For example, a tree can be defined as a connected graph which contains no cycles, and Kuratowski [22] characterized plan...

متن کامل

Forbidden subgraphs in connected graphs

Given a set ξ = {H1,H2, · · ·} of connected non acyclic graphs, a ξ-free graph is one which does not contain any member of ξ as copy. Define the excess of a graph as the difference between its number of edges and its number of vertices. Let Ŵk,ξ be theexponential generating function (EGF for brief) of connected ξ-free graphs of excess equal to k (k ≥ 1). For each fixed ξ, a fundamental differen...

متن کامل

Forbidden Subgraphs and Cycle Extendability

A graph G on n vertices is pancyclic if G contains cycles of all lengths`for 3 ` n and G is cycle extendable if for every nonhamiltonian cycle C G there is a cycle C 0 G such that V (C) V (C 0) and jV (C 0) n V (C)j = 1. We prove that (i) every 2-connected K 1;3-free graph is pancyclic, if G is P 5-free and n 6, if G is P 6-free and n 10, or if G is P 7-free, deer-free and n 14, and (ii) every ...

متن کامل

Disjoint Stars and Forbidden Subgraphs

Let r, k be integers with r ≥ 3, k ≥ 2. We prove that if G is a K1,rfree graph of order at least (k− 1)(2r − 1) + 1 with δ(G) ≥ 2, then G contains k vertex-disjoint copies of K1,2. This result is motivated by characterizing a forbidden subgraph H which satisfies the statement “every H-free graph of sufficiently large order with minimum degree at least t contains k vertex-disjoint copies of a st...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Notre Dame Journal of Formal Logic

سال: 1978

ISSN: 0029-4527

DOI: 10.1305/ndjfl/1093888225