[ont.events] On Regular Trace Languages

ylfink@water.UUCP (11/10/87)

DEPARTMENT OF COMPUTER SCIENCE
UNIVERSITY OF WATERLOO
SEMINAR ACTIVITIES

FORMAL LANGUAGE THEORY SEMINAR

                    - Thursday, November 12, 1987

Dr.    Jacques    Sakarovitch,   of   the   Laboratoire
Informatique Theorique et Programmation, Paris, France,
will  speak  on ``On Regular Trace Languages (And Other
Stories)''.

TIME:                3:30 PM

ROOM:              MC 6082

ABSTRACT

The starting point of the work that will be reported in
the  seminar  is  the  characterization  of commutation
relations  with  the  property  that  the corresponding
regular    trace    languages    are    closed    under
complementation  or  are  unambiguous.   This  will  be
established  as  a  consequence  of  a property of free
products (of monoids).  This property, in turn, will be
proved  by means of a generalization of finite automata
(that  has  been  more  or less folklore up to now) and
that  gives  new insights on several classical results,
as Chomsky normal form for context-free grammars.