on notation, MM', graph theory, incidence matrix product

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From	Daniel Bastos <dbastos@toledo.com>
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Subject	on notation, MM', graph theory, incidence matrix product
Date	Sat, 16 Sep 2017 11:26:57 -0300
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Problem.  Show that if G is simple, the entries on the diagonals of both
MM' and A^2 are the degrees of the vertices of G.

I don't understand what is meant by MM'.  M is the incidence matrix of
graph G.  By looking at section 1.4, subgraphs, I take that M' must be
the incidence matrix of some subgraph induced by M, but M is a matrix,
so I'm puzzled.  AFAIK, I need a set of vertices of a set of edges to
induce a subgraph.

I appreciate a clarification on the book's notation.  Thank you!

This is problem 1.5.2 in ``Graph theory with applications'' by
J.A. Bondy and U.S.R. Murty, Department of Combinatorics and
Optimization, University of Waterloo, Ontario, Canada.  North-Holland,
fifth printing, 1982.  ISBN: 0-444-19451-7.

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on notation, MM', graph theory, incidence matrix product Daniel Bastos <dbastos@toledo.com> - 2017-09-16 11:26 -0300
  Re: on notation, MM', graph theory, incidence matrix product Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-09-16 16:39 +0100
    Re: on notation, MM', graph theory, incidence matrix product Daniel Bastos <dbastos@toledo.com> - 2017-09-17 07:51 -0300

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