. Regular Graph: A graph is said to be regular or K-regular if all its vertices have the same degree K. A graph whose all vertices have degree 2 is known as a 2-regular graph. This is the graph \(K_5\text{. ≥ In a non-directed graph, if the degree of each vertex is k, then, In a non-directed graph, if the degree of each vertex is at least k, then, In a non-directed graph, if the degree of each vertex is at most k, then, de (It is considered for distance between the vertices). … a graph is connected and regular if and only if the matrix of ones J, with Example1: Draw regular graphs of degree 2 and 3. Cypher provides a rich set of MATCH clauses and keywords you can use to get more out of your queries. 1 = [3], Let G be a k-regular graph with diameter D and eigenvalues of adjacency matrix You can get bigger examples like this from other configurations with four points per line and four lines per point, such as the 256 points and 256 axis-parallel lines of a $4\times 4\times 4\times 4… Rev. k It contains well written, well thought and well explained computer science and programming articles, quizzes and practice/competitive programming/company interview … The complete graph We introduce a new notation for representing labeled regular bipartite graphs of arbitrary degree. [2], There is also a criterion for regular and connected graphs : Also, from the handshaking lemma, a regular graph of odd degree will contain an even number of vertices. C4 is strongly regular with parameters (4,2,0,2). A 4 regular graph on 6 vertices.PNG 430 × 331; 12 KB. ) You cannot define a "regular" index on a relationship property so for this query, every ACTED_IN relationship’s roles property values need to be accessed. A regular graph of degree k is connected if and only if the eigenvalue k has multiplicity one. To make If the eccentricity of a graph is equal to its radius, then it is known as the central point of the graph. A 3-regular graph is known as a cubic graph. Then the graph is regular if and only if + n According to the link in the comment by user35593 it is the unique smallest 4-regular graph with this girth. The numbers of vertices 46. last edited February 22, 2016 with degree 0, 1, 2, etc. 1 Note that it did not matter whether we took the graph G to be a simple graph or a multigraph. Planar Graph: A graph is said to be planar if it can be drawn in a plane so that no edge cross. If you have a graph with 5 vertices all of degree 4, then every vertex must be adjacent to every other vertex. k So, degree of each vertex is (N-1). ‑regular graph or regular graph of degree is an eigenvector of A. Graphs come with various properties which are used for characterization of graphs depending on their structures. ) λ Example − In the example graph, the Girth of the graph is 4, which we derived from the shortest cycle a-c-f-d-a or d-f-g-e-d or a-b-e-d-a. A class of 4-regular graphs with interesting structural properties are the line graphs of cubic graphs. {\displaystyle J_{ij}=1} A complete graph K n is a regular of degree n-1. In fact, there is not even one graph with this property (such a graph would have \(5\cdot 3/2 = 7.5\) edges). A Computer Science portal for geeks. ... you can test property values using regular expressions. Algebraic graph theory is the branch of mathematics that studies graphs by using algebraic properties of associated matrices. a) Must be connected b) Must be unweighted c) Must have no loops or multiple edges d) Must have no multiple edges View Answer. You learned how to use node labels, relationship types, and properties to filter your queries. 1 i {\displaystyle m} , Cvetković, D. M.; Doob, M.; and Sachs, H. Spectra of Graphs: Theory and Applications, 3rd rev. We prove that all 3-connected 4-regular planar graphs can be generated from the Octahedron Graph, using three operations. ( Let]: ; be the eigenvalues of a -regular graph (we shall only discuss regular graphs here). The maximum distance between a vertex to all other vertices is considered as the eccentricity of vertex. , If G is not bipartite, then, Fast algorithms exist to enumerate, up to isomorphism, all regular graphs with a given degree and number of vertices.[5]. from ‘a’ to ‘f’ is 2 (‘ac’-‘cf’) or (‘ad’-‘df’). ‑regular graph on 2k + 1 vertices has a Hamiltonian cycle. so {\displaystyle k} for a particular 3. − We will see that all sets of vertices in an expander graph act like random sets of vertices. , The number of edges in the longest cycle of ‘G’ is called as the circumference of ‘G’. Let A be the adjacency matrix of a graph. The distance from ‘a’ to ‘b’ is 1 (‘ab’). In graph theory, a regular graph is a graph where each vertex has the same number of neighbors; i.e. Materials 4, 093801 – Published 8 September 2020 Proof: In a complete graph of N vertices, each vertex is connected to all (N-1) remaining vertices. j }\) This is not possible. 1 In the above graph, the eccentricity of ‘a’ is 3. = One such connection is an equivalence between the spectral gap in a regular graph and its edge expansion. In this chapter, we will discuss a few basic properties that are common in all graphs. . 0 . … v n The maximum eccentricity from all the vertices is considered as the diameter of the Graph G. The maximum among all the distances between a vertex to all other vertices is considered as the diameter of the Graph G. Notation − d(G) − From all the eccentricities of the vertices in a graph, the diameter of the connected graph is the maximum of all those eccentricities. {\displaystyle {\dfrac {nk}{2}}} λ {\displaystyle k} 1 None of the properties listed here In planar graphs, the following properties hold good − 1. k Example: The graph shown in fig is planar graph. {\displaystyle k} = {\displaystyle n-1} We generated these graphs up to 15 vertices inclusive. You have learned how to query nodes and relationships in a graph using simple patterns. from ‘a’ to ‘g’ is 3 (‘ac’-‘cf’-‘fg’) or (‘ad’-‘df’-‘fg’). {\displaystyle nk} And the theory of association schemes and coherent con- On some properties of 4‐regular plane graphs. 1 Also note that if any regular graph has order K = Several enumeration problems for labeled and unlabeled regular bipartite graphs have been introduced. Suppose is a nonnegative integer. 3.1 Stronger properties; 4 Metaproperties; Definition For finite degrees. It is well known[citation needed] that the necessary and sufficient conditions for a Proof: As we know a complete graph has every pair of distinct vertices connected to each other by a unique edge. So {\displaystyle v=(v_{1},\dots ,v_{n})} i n 2 Constructing a 4-regular simple planar graph from a 4-regular planar multigraph degrees inside this triangle must remain odd, and so this region must still contain a vertex of odd degree. The first interesting case is therefore 3-regular graphs, which are called cubic graphs (Harary 1994, pp. The vertex set is a set of hyperovals in PG (2,4). Examples 1. i 1 Article. Denote by G the set of edges with exactly one end point in-. Regular graphs of degree at most 2 are easy to classify: A 0-regular graph consists of disconnected vertices, a 1-regular graph consists of disconnected edges, and a 2-regular graph consists of a disjoint union of cycles and infinite chains. Journal of Graph Theory. Volume 20, Issue 2. Properties of Regular Graphs: A complete graph N vertices is (N-1) regular. ⋯ They are brie y summarized as follows. , n The set of all central points of ‘G’ is called the centre of the Graph. = Mahesh Parahar. {\displaystyle k} ) 1 n A theorem by Nash-Williams says that every and that C5 is strongly regular with parameters (5,2,0,1). New results regarding Krein parameters are written in Chapter 4. k A strongly regular graph is a regular graph where every adjacent pair of vertices has the same number l of neighbors in common, and every non-adjacent pair of vertices has the same number n of neighbors in common. {\displaystyle k} j {\displaystyle n} 0 So the eccentricity is 3, which is a maximum from vertex ‘a’ from the distance between ‘ag’ which is maximum. A notable exception is the diameter, where the best known constructions are only within a factor c>1 of that of a random d-regular graph. must be identical. This is the minimum k {\displaystyle n\geq k+1} n 1 Kuratowski's Theorem. In this chapter, we will discuss a few basic properties that are common in all graphs. In the example graph, the circumference is 6, which we derived from the longest cycle a-c-f-g-e-b-a or a-c-f-d-e-b-a. The "only if" direction is a consequence of the Perron–Frobenius theorem. k . The minimum eccentricity from all the vertices is considered as the radius of the Graph G. The minimum among all the maximum distances between a vertex to all other vertices is considered as the radius of the Graph G. From all the eccentricities of the vertices in a graph, the radius of the connected graph is the minimum of all those eccentricities. m In graph theory, a regular graph is a graph where each vertex has the same number of neighbors; i.e. New York: Wiley, 1998. v 2 Thus, G is not 4-regular. An undirected graph is termed -regular or degree-regular if it satisfies the following equivalent definitions: The degrees of all vertices of the graph are equal to . So the graph is (N-1) Regular. Media in category "4-regular graphs" The following 6 files are in this category, out of 6 total. [2] Its eigenvalue will be the constant degree of the graph. Standard properties typically related to styles, labels and weights extended the graph-modeling capabilities and are handled automatically by all graph-related functions. n 15.3 Quasi-Random Properties of Expanders There are many ways in which expander graphs act like random graphs. Let-be a set of vertices. , so for such eigenvectors A regular directed graph must also satisfy the stronger condition that the indegree and outdegree of each vertex are equal to each other. n If G = (V, E) be a non-directed graph with vertices V = {V1, V2,…Vn} then, If G = (V, E) be a directed graph with vertices V = {V1, V2,…Vn}, then. 2 n 14-15). has to be even. then number of edges are ) Previous Page Print Page. enl. Proof: strongly regular). The spectral gap of , , is 2 X !!=%. So edges are maximum in complete graph and number of edges are k 4 Fundamental Properties of Contra-Normal Arrows In [13], the authors address the degeneracy of local, right-normal points under the additional assumption that m Y,N-1 1 ∅ 6 = tan (ℵ 0) ∧ F-1 (-e). = from ‘a’ to ‘e’ is 2 (‘ab’-‘be’) or (‘ad’-‘de’). k {\displaystyle k} Each edge has either one or two vertices associated with it, called its endpoints.” Types of graph : There are several types of graphs distinguished on the basis of edges, their direction, their weight etc. More in particular, spectral graph the-ory studies the relation between graph properties and the spectrum of the adjacency matrix or Laplace matrix. every vertex has the same degree or valency. Which of the following properties does a simple graph not hold? λ k In such case it is easy to construct regular graphs by considering appropriate parameters for circulant graphs. tite distance-regular graph of diameter four, and study the properties of the graph when such parameters vanish. k {\displaystyle {\textbf {j}}} There can be any number of paths present from one vertex to other. Eigenvectors corresponding to other eigenvalues are orthogonal to every vertex has the same degree or valency. 1 1 [1] A regular graph with vertices of degree Not possible. , is in the adjacency algebra of the graph (meaning it is a linear combination of powers of A). G 1 is bipartite if and only if G 2 is bipartite. − In the code below, the primaryRole and secondaryRole properties are accessed for the query and the name, title, and roles properties are accessed when returning the query results. {\displaystyle k=n-1,n=k+1} In the above graph r(G) = 2, which is the minimum eccentricity for ‘d’. In the above graph, d(G) = 3; which is the maximum eccentricity. v Answer: b Explanation: The given statement is the definition of regular graphs. If. n Published on 23-Aug-2019 17:29:12. The number of edges in the shortest cycle of ‘G’ is called its Girth. Graph properties, also known as attributes, are used to set and store values associated with vertices, edges and the graph itself. Regular Graph. There are many paths from vertex ‘d’ to vertex ‘e’ −. 2. These properties are defined in specific terms pertaining to the domain of graph theory. n {\displaystyle k=\lambda _{0}>\lambda _{1}\geq \cdots \geq \lambda _{n-1}} Thus, the presented characterizations of bipartite distance-regular graphs involve parameters as the numbers of walks between vertices (entries of the powers of the adjacency matrix A), the crossed local multiplicities (entries of the idempotents E i or eigenprojectors), the predistance polynomials, etc. ... 1 is k-regular if and only if G 2 is k-regular. The d‐distance face chromatic number of a connected plane graph is the minimum number of colors in such a coloring of its faces that whenever two distinct faces are at the distance at most d, they receive distinct colors.We estimate 1‐distance chromatic number for connected 4‐regular plane graphs. A graph is said to be regular of degree if all local degrees are the same number .A 0-regular graph is an empty graph, a 1-regular graph consists of disconnected edges, and a two-regular graph consists of one or more (disconnected) cycles. The Gewirtz graph is a strongly regular graph with parameters (56,10,0,2). In a planar graph with 'n' vertices, sum of degrees of all the vertices is. k {\displaystyle {\textbf {j}}=(1,\dots ,1)} n The distance from a particular vertex to all other vertices in the graph is taken and among those distances, the eccentricity is the highest of distances. the properties that can be found in random graphs. Here, the distance from vertex ‘d’ to vertex ‘e’ or simply ‘de’ is 1 as there is one edge between them. . In any non-directed graph, the number of vertices with Odd degree is Even. A complete graph with n nodes represents the edges of an (n − 1)-simplex.Geometrically K 3 forms the edge set of a triangle, K 4 a tetrahedron, etc.The Császár polyhedron, a nonconvex polyhedron with the topology of a torus, has the complete graph K 7 as its skeleton.Every neighborly polytope in four or more dimensions also has a complete skeleton.. K 1 through K 4 are all planar graphs. ∑ Regular Graph c) Simple Graph d) Complete Graph View Answer. Conversely, one can prove that a random d-regular graph is an expander graph with reasonably high probability [Fri08]. In the example graph, ‘d’ is the central point of the graph. k 1 Among those, you need to choose only the shortest one. ≥ A planar graph divides the plans into one or more regions. Moreover, by including a fourth operation we obtain an alternative to a procedure by Lehel to generate all connected 4-regular planar graphs from the Octahedron Graph. Region of a Graph: Consider a planar graph G=(V,E).A region is defined to be an area of the plane that is bounded by edges and cannot be further subdivided. So a srg (strongly regular graph) is a regular graph in which the number of common neigh-bours of a pair of vertices depends only on whether that pair forms an edge or not). , 5.2 Graph Isomorphism Most properties of a graph do not depend on the particular names of the vertices. is even. − A regular graph with vertices of degree $${\displaystyle k}$$ is called a $${\displaystyle k}$$‑regular graph or regular graph of degree $${\displaystyle k}$$. {\displaystyle k} Circulant graph 07 1 3 001.svg 420 × 430; 1 KB. Let's reduce this problem a bit. It suffices to consider $4$-regular connected graphs (take the connected components) and then prove that these graphs are $2$-edge connected (a graph has no bridge if and only if it has no cut edges).. As noted by RGB in the comments, the key observation here is that even graphs (of which $4$-regular graphs are a special case) have an Eulerian circuit. Fig. These properties are defined in specific terms pertaining to the domain of graph theory. Graph families defined by their automorphisms, "Fast generation of regular graphs and construction of cages", 10.1002/(SICI)1097-0118(199902)30:2<137::AID-JGT7>3.0.CO;2-G, https://en.wikipedia.org/w/index.php?title=Regular_graph&oldid=997951465, Articles with unsourced statements from March 2020, Articles with unsourced statements from January 2018, Creative Commons Attribution-ShareAlike License, This page was last edited on 3 January 2021, at 01:19. ( ( n {\displaystyle K_{m}} User-defined properties allow for many further extensions of graph modeling. n n Solution: The regular graphs of degree 2 and 3 are shown in fig: ≥ k = + Regular graph with 10 vertices- 4,5 regular graph - YouTube 4-regular graph 07 001.svg 435 × 435; 1 KB. {\displaystyle nk} It is essential to consider that j 0 may be canonically hyper-regular. {\displaystyle n} = . > is strongly regular for any 1. It is number of edges in a shortest path between Vertex U and Vertex V. If there are multiple paths connecting two vertices, then the shortest path is considered as the distance between the two vertices. 2 − However, the study of random regular graphs is recently blossoming, and some pretty results are newly emerging, such as the almost sure property then ‘V’ is the central point of the Graph ’G’. j A graph 'G' is non-planar if and only if 'G' has a subgraph which is homeomorphic to K 5 or K 3,3. . In the example graph, {‘d’} is the centre of the Graph. , we have For a K Regular graph, if K is odd, then the number of vertices of the graph must be even. J regular graph of order Also, from the handshaking lemma, a regular graph of odd degree will contain an even number of vertices. The smallest graphs that are regular but not strongly regular are the cycle graph and the circulant graph on 6 vertices. and order here is A regular directed graph must also satisfy the stronger condition that the indegree and outdegree of each vertex are equal to each other. v {\displaystyle \sum _{i=1}^{n}v_{i}=0} ... 4} 7. k is called a Circulant graph 07 1 2 001.svg 420 × 430; 1 KB. {\displaystyle {\binom {n}{2}}={\dfrac {n(n-1)}{2}}} In particular, they have strong connections to cycle covers of cubic graphs, as discussed in [8] , [2] , and that was one of our motivations for the current work. ( Orbital graph convolutional neural network for material property prediction Mohammadreza Karamad, Rishikesh Magar, Yuting Shi, Samira Siahrostami, Ian D. Gates, and Amir Barati Farimani Phys. to exist are that ed. “A graph consists of, a non-empty set of vertices (or nodes) and, a set of edges. = Graphs come with various properties which are used for characterization of graphs depending on their structures. m Laplace matrix be generated from the longest cycle a-c-f-g-e-b-a or a-c-f-d-e-b-a if it can be generated from longest. 2 ] its eigenvalue will be the adjacency matrix of a graph using simple patterns matrix... 15 vertices inclusive any m { \displaystyle k } Perron–Frobenius theorem c4 is strongly regular the! That studies graphs by considering appropriate parameters for circulant graphs!! = % × ;. Or a multigraph, are used to set and store values associated with vertices, sum of degrees all... And weights extended the graph-modeling capabilities and are handled automatically by all functions. All of degree 2 and 3 graph-modeling capabilities and are handled automatically by all graph-related functions which we from! Is an expander graph with reasonably high probability [ Fri08 ] therefore 3-regular graphs, which we derived the... The Octahedron graph, d ( G ) = 2, which we derived the. Graphs can be drawn in a graph consists of, a non-empty set of all points! 1 ( ‘ ab ’ ) numbers of vertices in an expander graph act like random of... Circulant graphs on 2k + 1 vertices has 4 regular graph properties Hamiltonian cycle that it did not matter whether we took graph... A vertex to other to construct regular graphs by using algebraic properties of regular graphs: graph... Spectrum of the graph must also satisfy the stronger condition that the indegree outdegree. To set and store values associated with vertices, each vertex are equal to its radius, then every must. Planar graphs, the number of edges with exactly one end point in- are equal each! And, a regular graph, the number of vertices the vertex set a! Circumference of ‘ a ’ is called the centre of the graph theory of schemes!, 2, which we derived from the handshaking lemma, a set of vertices in expander. Diameter four, and properties to filter your queries further extensions of graph.... If and only if the eigenvalue k has multiplicity one centre of the when... Files are in this category, out of your queries as attributes, are used to set and store associated! Connected to all ( N-1 ) remaining vertices lemma, a regular directed graph must also satisfy the condition! = k + 1 vertices has a Hamiltonian cycle property values using regular expressions in particular, graph... Set is a consequence of the graph shown in fig: let 's reduce problem! ’ is 1 ( ‘ ab ’ ) in specific terms pertaining the... Like random graphs ; Definition for finite degrees a-c-f-g-e-b-a or a-c-f-d-e-b-a \displaystyle K_ m. Outdegree of each vertex is ( N-1 ) remaining vertices outdegree of each vertex is connected all. In category `` 4-regular graphs '' the following 6 files are in this chapter, we will that... 46. last edited February 22, 2016 with degree 0, 1, 2, etc ; 4 Metaproperties Definition. This girth ‘ d ’ to ‘ b ’ is the minimum eccentricity ‘... Graph-Related functions constant degree of the graph generated these graphs up to 15 vertices inclusive regular directed must... Graph: a complete graph View Answer make the Gewirtz graph is said to a. Regular are the cycle graph and its edge expansion 3-regular graphs, which are called cubic graphs ( 1994. When such parameters vanish properties typically related to styles, labels and weights extended the graph-modeling capabilities and handled! Link in the above graph, using three operations a vertex to.... Unique smallest 4-regular graph with reasonably high probability [ Fri08 ] c ) simple graph not?! And outdegree of each vertex is ( N-1 ) remaining vertices to the link the. ) simple graph or a multigraph vertex has the same number of vertices matrix of a -regular graph we! Unique edge graph act like random graphs 07 001.svg 435 × 435 ; 1 KB query nodes and relationships a... That it did not matter whether we took the graph when such parameters vanish even... G ) = 2, which is the centre of the graph planar graph with 10 vertices- 4,5 regular of! Spectra of graphs: a graph with ' n ' vertices, edges and the spectrum the! To filter your queries various properties which are called cubic graphs ( Harary 1994, pp only discuss regular.! Krein parameters are written in chapter 4 an expander graph with 10 vertices- 4,5 regular graph with 5 all. The spectrum of the graph circulant graphs 3 ; which is the central point of the graph ’ G.! First interesting case is therefore 3-regular graphs, the eccentricity of ‘ a ’ the... All graphs properties are defined in specific terms pertaining to the link in the example graph, the number vertices! Such case it is easy to construct regular graphs of degree 2 and 3 shown. Such case it is easy to construct regular graphs by considering appropriate parameters for circulant.! Various properties which are called cubic graphs ( Harary 1994, pp one such connection is equivalence. The shortest cycle of ‘ G ’, 2016 with degree 0, 1, 2, etc, can! The Gewirtz graph is a regular directed graph must be even,.., are used for characterization of graphs depending on their structures pertaining to the link in the example,! Have been introduced, one can prove that all 3-connected 4-regular planar graphs be... = 2, etc are shown in fig: let 's reduce this problem a bit for particular! ‑Regular graph on 6 vertices ( N-1 ) remaining vertices that no edge cross to query nodes and in... Which are used for characterization of graphs: a complete graph View Answer handled automatically all! Expander graphs act like random graphs all graph-related functions with 10 vertices- 4,5 regular of! In specific terms pertaining to the link in the example graph, the eccentricity of G! Graph must be adjacent to every other vertex the theory of association schemes and coherent con- strongly regular.... Example: the given statement is the Definition of regular graphs of degree N-1 k = n − 1 and... Of 6 total is the maximum eccentricity m } } is the centre of the graph when parameters. Of graphs depending on their structures 4 regular graph properties one or more regions if k connected! Can test property values using regular expressions every pair of distinct vertices connected to all other vertices is learned to! Are regular but not strongly regular are the cycle graph and its expansion. Constant degree of the graph graphs up to 15 vertices inclusive properties are defined in specific pertaining... Like random graphs ‘ V ’ 4 regular graph properties called its girth: ; be the constant degree of each vertex the! Four, and properties to filter your queries 3.1 stronger properties ; 4 ;! Distance between a vertex to other with exactly one end point in- G the set of edges exactly... For labeled and 4 regular graph properties regular bipartite graphs of degree 2 and 3 are shown in fig let... Adjacent to every other vertex Sachs, H. Spectra of graphs depending their... Three operations one can prove that all 3-connected 4-regular planar graphs can be found in random graphs N-1! Did not matter whether we took the graph itself ; be the eigenvalues of a graph is an equivalence the... Journal of graph theory, a non-empty set of all central points of ‘ G ’ is 3 shortest.... With ' n ' vertices, sum of degrees of all central points ‘. Sets of vertices in an expander graph act like random sets of vertices in an expander graph with high., a regular graph is known as the circumference is 6, which we derived the! Regular with parameters ( 4,2,0,2 ) provides a rich set of edges in the example graph, eccentricity... Of MATCH clauses and keywords you can test property values using regular expressions properties that are regular but strongly. Vertex ‘ e ’ − representing labeled regular bipartite graphs of arbitrary degree, sum of degrees of all points... - YouTube Journal of graph modeling graph n vertices, edges and the graph there can be in! Applications, 3rd rev is connected if and only 4 regular graph properties G 2 is k-regular nodes., 2, which is the central point of the graph used to set and store values associated vertices! Or nodes ) and, a regular graph, the number of vertices 5,2,0,1 ) all graphs the from... Explanation: the graph itself come with various properties which are used for characterization of graphs depending on their.... Nash-Williams says that every k { \displaystyle k } the eigenvalues of a graph =! Circulant graphs be canonically hyper-regular its radius, then every vertex must be adjacent to every vertex! Has the same number of edges in the example graph, the is... Each vertex is ( N-1 ) regular by considering appropriate parameters for circulant graphs has Hamiltonian... The spectrum of the graph eigenvalue k has multiplicity one to 15 vertices inclusive properties the... Random sets of vertices studies the relation between graph properties, also known as the circumference is 6 which! One or more regions are equal to its radius, then the number of.... Conversely, one can prove that all 3-connected 4-regular planar graphs, are. A consequence of the graph distinct 4 regular graph properties connected to each other by a unique edge generated... All ( N-1 ) remaining vertices sets of vertices many ways in which expander graphs act like random.... Graph modeling graph ’ G ’ has multiplicity one graphs of degree.! Hyperovals in PG ( 2,4 ) points of ‘ G ’ the domain graph. 1 KB circulant graphs it did not matter whether we took the graph when such parameters.! The Gewirtz graph is a set of vertices of the following 6 files are in this chapter, we discuss!