Proof Pearl: A Probabilistic Proof for the Girth-Chromatic Number Theorem

نویسنده

  • Lars Noschinski
چکیده

The Girth-Chromatic number theorem is a theorem from graph theory, stating that graphs with arbitrarily large girth and chromatic number exist. We formalize a probabilistic proof of this theorem in the Isabelle/HOL theorem prover, closely following a standard textbook proof and use this to explore the use of the probabilistic method in a theorem prover.

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

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

A Probabilistic Proof of the Girth-Chromatic Number Theorem

This works presents a formalization of the Girth-Chromatic number theorem in graph theory, stating that graphs with arbitrarily large girth and chromatic number exist. The proof uses the theory of Random Graphs to prove the existence with probabilistic arguments and is based on [1].

متن کامل

عدد تناوبی گراف‌ها

In 2015, Alishahi and Hajiabolhassan introduced the altermatic number of graphs as a lower bound for the chromatic number of them. Their proof is based on the Tucker lemma, a combinatorial counterpart of the Borsuk-Ulam theorem, which is a well-known result in topological combinatorics. In this paper, we present a combinatorial proof for the Alishahi-Hajiabolhassan theorem. 

متن کامل

A New Proof of the Girth - Chromatic Number Theorem

We give a new proof of the classical Erdös theorem on the existence of graphs with arbitrarily high chromatic number and girth. Rather than considering random graphs where the edges are chosen with some carefully adjusted probability, we use a simple counting argument on a set of graphs with bounded vertex degree.

متن کامل

Almost all graphs with high girth and suitable density have high chromatic number

Erdős proved that there exist graphs of arbitrarily high girth and arbitrarily high chromatic number. We give a different proof (but also using the probabilistic method) that also yields the following result on the typical asymptotic structure of graphs of high girth: for all ` ≥ 3 and k ∈ N there exist constants C1 and C2 so that almost all graphs on n vertices and m edges whose girth is great...

متن کامل

High Girth Hypergraphs with Unavoidable Monochromatic or Rainbow Edges

A classical result of Erdős and Hajnal claims that for any integers k, r, g ≥ 2 there is an r-uniform hypergraph of girth at least g with chromatic number at least k. This implies that there are sparse hypergraphs such that in any coloring of their vertices with at most k − 1 colors there is a monochromatic hyperedge. We show that for any integers r, g ≥ 2 there is an r-uniform hypergraph of gi...

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

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

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2012