BEGIN:VCALENDAR
VERSION:2.0
PRODID:ILLC Website
BEGIN:VEVENT
UID:/NewsandEvents/Events/Upcoming-Events/newsitem
/7045/18-November-2015-Algebra|Coalgebra-Seminar-A
lberto-Gatto
DTSTAMP:20151108T000000
SUMMARY:Algebra|Coalgebra Seminar, Alberto Gatto
ATTENDEE;ROLE=Speaker:Alberto Gatto
DTSTART:20151118T171500
DTEND:20151118T181500
LOCATION:Room F3.20, Science Park 107, Amsterdam
DESCRIPTION:I will introduce the first-order langu
ages L2 and Lt (from 'Topological model theory' by
Flum and Ziegler), and the modal language Lm with
derivative and counting operators. I will then il
lustrate original work which establishes the equiv
alence between Lt and Lm over T3 spaces, and that
the result fails over T2 spaces. I will then prese
nt a recent axiomatisation of the Lm theory of the
classes of all T3, T2, and T1 spaces. I will then
discuss the open problem of proving that Lm enric
hed with only finitely many other modal operators
is still less expressive than Lt over T2 spaces, a
nd present some partial results. Finally, I will c
onclude by illustrating possible directions of fut
ure work. For more information, see http://www.il
lc.uva.nl/alg-coalg or contact Frederik Lauridsen
(f.m.lauridsen at uva.nl) or Julia Ilin (ilin.juli
at gmail.com).
X-ALT-DESC;FMTTYPE=text/html:\n I will i
ntroduce the first-order languages L2 and Lt (from
'Topological model theory' by Flum and Ziegler),
and the modal language Lm with derivative and coun
ting operators. I will then illustrate original wo
rk which establishes the equivalence between Lt an
d Lm over T3 spaces, and that the result fails ove
r T2 spaces. I will then present a recent axiomati
sation of the Lm theory of the classes of all T3,
T2, and T1 spaces. I will then discuss the open pr
oblem of proving that Lm enriched with only finite
ly many other modal operators is still less expres
sive than Lt over T2 spaces, and present some part
ial results. Finally, I will conclude by illustrat
ing possible directions of future work.

\n \
n For more information, see htt
p://www.illc.uva.nl/alg-coalg or contact Frede
rik Lauridsen (f.m.lauridsen at uva.nl) or Julia Ilin (
ilin.juli at gmail.com).

\n
URL:/NewsandEvents/Events/Upcoming-Events/newsitem
/7045/18-November-2015-Algebra|Coalgebra-Seminar-A
lberto-Gatto
END:VEVENT
END:VCALENDAR