Introduction to better-quasi-orderings
Speaker: Linda Westrick, Penn State University
Abstract: We give an introduction to the theory of better-quasi-orderings (BQOs) as defined by Nash-Williams 1965 paper "On well-quasi-ordering infinite trees". Well-quasi-orderings (WQOs), which are quasi-orderings that have no infinite antichains or strictly descending sequences, have been repeatedly and independently defined; the stronger, stranger, but better-behaved notion of a BQO has made it possible to verify the WQO-ness of certain quasi-orders, via showing that they are actually BQO.
Room Reservation Information
Room Number: 315 McAllister
Time: 2:30pm - 4:00pm