The seminar meets on Wednesday 20th at 11:00 in the Institute of
Mathematics CAS, Zitna 25, seminar room, 3rd floor, front building.
Jonathan Verner will deliver a short talk on the topic announced below.
There will probably be a enough time for one more talk, volunteer
speakers are welcome.
M. Krom: A linearly ordered topological space which is not normal
Recall that in an introductory course in topology one learns that every
linearly ordered topological space is normal. If the course is good, it
is also pointed out that the construction requires the axiom of choice.
In this talk we will present a nice construction, due to Melven Krom,
which uses a specific instance of the failure of AC to build a linearly
ordered topological space which is not normal. Krom’s construction
answered an, at the time, long standing open question of Birkhoff.