Abstract. A kernel N of a digraph D is an independent set of vertices of D such that for every w ∈ V(D) − N there exists an arc from w to N. If every induced ...

wЄ V(D) - N there exists an arc from w to N. If every induced subdigraph of D has a kernel. D is said to be an R-digraph. Minimal non-R-digraphs are called ...

A kernel N of a digraph D is an independent set of vertices of D such that for every w ∈ V(D) − N there exists an arc from w to N. If every induced ...

A kernel N of a digraph D is an independent set of vertices of D such that for every w ~ V(D)- N there exists an arc from w to N. If every induced ...

Let D be a digraph, possibly infinite, V (D )a ndA(D) denote the sets of vertices and arcs of D, respectively. Ak ernelN of D is an independent set of ...

Abstract. Let D be a digraph with minimum indegree at least one. The following results are proved: a digraph D has a semikernel if and only if its line ...

It is proved that the number of semikernels (quasi kernels) of a digraph D is less than or equal to the number of semikernels (quasi kernels) of its line ...

Abstract. Let D be a digraph with minimum indegree at least one. The following results are proved: a digraph D has a semikernel if and only if its line ...

Let D be a finite digraph, V(D) and A(D) will denote the sets of vertices and arcs of D respectively. A kernel N of D is an independent set of vertices such ...

Jan 28, 2016 · In this paper we prove the following results: Let k,l be two natural numbers such that 1\le l \le k, and D a digraph with minimum in-degree at ...