Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!iuvax!cica!tut.cis.ohio-state.edu!ucbvax!ADS.COM!marcel
From: marcel@ADS.COM (Marcel Schoppers)
Newsgroups: comp.theory
Subject: dual graphs and co-automata
Message-ID: <9006011620.AA05038@irt.watson.ibm.com>
Date: 1 Jun 90 16:20:43 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Reply-To: Marcel Schoppers <marcel%ads.com@VM1.NoDak.EDU>
Organization: Advanced Decision Systems, Mt. View, CA (415) 960-7300
Lines: 15

This problem might have been studied both under graph theory and under
automata theory:

To convert a graph or automaton into its dual you map edges/arcs of
the input structure into vertices/states of the dual structure, and
vertices/states of the input structure into edges/arcs of the dual.

The Question: If you know something about the input structure, what
do you know about the dual?  Of particular interest is what you know
about the dual when the input structure is an automaton that accepts
a prefix-closed or suffix-closed language.

Can someone give me a reference on the properties of duals?

Marcel