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Inequalities involving independence domination, f -domination, connected and total f -domination numbers

San Ming Zhou (2000)

Czechoslovak Mathematical Journal

Let f be an integer-valued function defined on the vertex set V ( G ) of a graph G . A subset D of V ( G ) is an f -dominating set if each vertex x outside D is adjacent to at least f ( x ) vertices in D . The minimum number of vertices in an f -dominating set is defined to be the f -domination number, denoted by γ f ( G ) . In a similar way one can define the connected and total f -domination numbers γ c , f ( G ) and γ t , f ( G ) . If f ( x ) = 1 for all vertices x , then these are the ordinary domination number, connected domination number and total domination...

Interpolation theorems for a family of spanning subgraphs

San Ming Zhou (1998)

Czechoslovak Mathematical Journal

Let G be a graph with order p , size q and component number ω . For each i between p - ω and q , let 𝒞 i ( G ) be the family of spanning i -edge subgraphs of G with exactly ω components. For an integer-valued graphical invariant ϕ , if H H ' is an adjacent edge transformation (AET) implies | ϕ ( H ) - ϕ ( H ' ) | 1 , then ϕ is said to be continuous with respect to AET. Similarly define the continuity of ϕ with respect to simple edge transformation (SET). Let M j ( ϕ ) and m j ( ϕ ) be the invariants defined by M j ( ϕ ) ( H ) = max T 𝒞 j ( H ) ϕ ( T ) , m j ( ϕ ) ( H ) = min T 𝒞 j ( H ) ϕ ( T ) . It is proved that both M p - ω ( ϕ ) and m p - ω ( ϕ ) interpolate...

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