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- Thread starter iany00
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- Thread starter
- #1

- Feb 5, 2012

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Hi iany00,G = (V, E) a graph with V = {1, . . . , n}. We have the function f : V → V defined

f (v) = min{u|u ∈ V, dG (v, u) ≤ 2}.

Demostrate that vw ∈ E(G) with f (v) != f (w) then G has the

P4 subgraph induced

I don;t understand what to demostrate/to do. Any advice?

I don't know the answer to your question, but the exact same question (although differently worded), is asked at Stack Exchange.

graph theory - Prove that if $G$ is P4-free then any two vertices $u$ and $v$ are in the same connected component if and only if $f(u) = f(v)$ - Mathematics

Hope this helps.

Kind Regards,

Sudharaka.