Time:  12:30  13:30 
Room: 
Wean Hall 8220

Speaker: 
Jing Zhang Department of Mathematical Sciences CMU 
Title: 
The forcing proof of the HalpernLäuchli theorem

Abstract: 
We will discuss Harrington's conceptually simple proof of the HalpernLäuchli theorem using the machinery of forcing. Also if time permits, we will also briefly discuss its role in establishing the theorem due to Halpern and Lévy: the Boolean Prime Ideal Theorem does not imply the Axiom of Choice over ZF. 