fl
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Question about linear algebra matrix pnorm
Posted:
Jan 7, 2013 11:50 PM


Hi, I am reading a book on matrix characters. It has a lemma on matrix pnorm. I do not understand a short explaination in its proof part.
The Lemma is: If F is Rnxn and Fp<1 (pnorm of F), then IF is nonsingular....
In its proof part, it says: Suppose IF is singular. It follows that (IF)x=0 for some nonzero x. But then x\p=Fxp implies Fp>=1, a contradiction. Thus, IF is nonsingular.
My question is about how it gets: But then x\p=Fxp implies Fp>=1
Could you tell me that? Thanks a lot

