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Score sets in oriented 3-partite graphs
Authors:S Pirzada  Merajuddin  T A Naikoo
Institution:(1) Department of Mathematics, University of Kashmir, Srinagar, 190006, India;(2) Department of Applied Mathematics, F/O Engineering and Tech., A.M.U. Aligarh, India;(3) Department of Mathematics, University of Kashmir, Srinagar, 190006, India
Abstract:Let D(U,V,W) be an oriented 3-partite graph with |U| = p, |V| = q and |W| = r. For any vertex x in D(U,V,W), let d x + and d x be the outdegree and indegree of x respectively. Define 
$$a_{u_i } $$
(or simply a i ) = q + r + 
$$d_{u_i }^ +   - d_{u_i }^ -  $$
, 
$$b_{v_j } $$
(or simply b j ) = p + r + d + ν j 
$$d_{v_j }^ -  $$
and 
$$c_{w_k } $$
(or simply c k ) = p + q + 
$$d_{w_k }^ +   - d_{w_k }^ -  $$
as the scores of u i in U,v j in V and w k in W respectively. The set A of distinct scores of the vertices of D(U,V,W) is called its score set. In this paper, we prove that if a 1 is a non-negative integer, a i (2 ≤ in − 1) are even positive integers and a n is any positive integer, then for n ≥ 3, there exists an oriented 3-partite graph with the score set 
$$A = \left\{ {a_1 ,\sum\limits_{i = 1}^2 {a_i , \cdots ,} \sum\limits_{i = 1}^n {a_i } } \right\}$$
, except when A = {0,2,3}. Some more results for score sets in oriented 3-partite graphs are obtained.
Keywords:oriented graph  oriented 3-partite graph  tournament score set  GRAPHS  ORIENTED  SETS  results  sets  graphs  integers  positive  prove  paper  score  vertex  oriented
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