A Constructive Proof of the Topological Kruskal Theorem

The Basic Theorem and its Consequences

Let T be a compact Hausdorff topological space and let M denote an n–dimensional subspace of the space C(T ), the space of real–valued continuous functions on T and let the space be equipped with the uniform norm. Zukhovitskii [7] attributes the Basic Theorem to E.Ya.Remez and gives a proof by duality. He also gives a proof due to Shnirel’man, which uses Helly’s Theorem, now the paper obtains a...

On Tychonoff's type theorem via grills

‎Let ${X_{alpha}:alphainLambda}$ be a collection of topological spaces‎, ‎and $mathcal {G}_{alpha}$ be a grill on $X_{alpha}$ for each $alphainLambda$‎. ‎We consider Tychonoffrq{}s type Theorem for $X=prod_{alphainLambda}X_{alpha}$ via the above grills and a natural grill on $X$ ‎related to these grills, and present a simple proof to this theorem‎. ‎This immediately yields the classical theorem...

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. 

FREE SEMIGROUPS AND IDEMPOTENTS IN T

The known theory for an oid T shows how to find a subset T of ?T, which is a compact right topological semigroup [I]. The success of the methods in [2] for obtaining properties of-T has prompted us to see how successful they would be in another context. Thus we find (Theorem 4.8) that T cont ains copies of free semigroups on 2? generators, is an immediate consequence of the stronger resu...

A constructive topological proof of van der Waerden's theorem