Handshaking lemma — In this graph, an even number of vertices (the four vertices numbered 2, 4, 5, and 6) have odd degrees. The sum of the degrees of the vertices is 2 + 3 + 2 + 3 + 3 + 1 = 14, twice the… … Wikipedia
Degree (graph theory) — A graph with vertices labeled by degree In graph theory, the degree (or valency) of a vertex of a graph is the number of edges incident to the vertex, with loops counted twice.[1] The degree of a vertex … Wikipedia
Double counting (proof technique) — In combinatorics, double counting, also called counting in two ways, is a combinatorial proof technique for showing that two expressions are equal by demonstrating that they are two ways of counting the size of one set. In this technique, which… … Wikipedia
List of lemmas — This following is a list of lemmas (or, lemmata , i.e. minor theorems, or sometimes intermediate technical results factored out of proofs). See also list of axioms, list of theorems and list of conjectures. 0 to 9 *0/1 Sorting Lemma ( comparison… … Wikipedia
Handshake — For the telecommunications concept, see Handshaking. Two men shaking hands A handshake is a short ritual in which two people grasp one of each other s like hands, in most cases accompanied by a brief up and down movement of the grasped hands … Wikipedia
Lemme de Sperner — Ne pas confondre avec le théorème de Sperner sur les familles d ensembles. En mathématiques, le lemme de Sperner, dû à Emanuel Sperner[1], est un analogue combinatoire du théorème du point fixe de Brouwer. Le lemme de Sperner affirme que… … Wikipédia en Français
Parity of zero — Zero objects, divided into two equal groups Zero is an even number. In other words, its parity the quality of an integer being even or odd is even. Zero fits the definition of even number : it is an integer multiple of 2, namely 0 × 2. As a… … Wikipedia
Route inspection problem — In graph theory, a branch of mathematics, the Chinese postman problem (CPP), postman tour or route inspection problem is to find a shortest closed path or circuit that visits every edge of a (connected) undirected graph. When the graph has an… … Wikipedia
Edge coloring — A 3 edge coloring of the Desargues graph. In graph theory, an edge coloring of a graph is an assignment of “colors” to the edges of the graph so that no two adjacent edges have the same color. For example, the figure to the right shows an edge… … Wikipedia
Cubic graph — Not to be confused with graphs of cubic functions. The Petersen graph is a Cubic graph … Wikipedia
