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The Restrained Edge Monophonic Number of a Graph
Authors: P. Titus, A. P. Santhakumaran and K. Ganesamoorthy
Number of views: 454
A set S of vertices of a connected graph G is a monophonic set if every vertex of G lies on an x−y monophonic path for some elements x and y in S. The minimum cardinality of a monophonic set of G is the monophonic number of G, denoted by m(G). A set S of vertices of a graph G is an edge monophonic set if every edge of G lies on an x − y monophonic path for some elements x and y in S. The minimum cardinality of an edge monophonic set of G is the edge monophonic number of G, denoted by em(G). A set S of vertices of a graph G is a restrained edge monophonic set if either V = S or S
is an edge monophonic set with the subgraph G[V −S] induced by V −S has no isolated vertices. The minimum cardinality of a restrained edge monophonic
set of G is the restrained edge monophonic number of G and is denoted by emr(G). It is proved that, for the integers a, b and c with 3 6 a 6 b < c, there exists a connected graph G having the monophonic number a, the edge monophonic number b and the restrained edge monophonic number c.