Friday, 6 March 2015  
14:00  14:30  Check in 
14:30  15:15  C. T. Chong (National Univ. of Singapore) 
Title : The coding LemmaAbstract


Coffee Break  
15:45  16:30  Emanuele Frittaion (Tohoku University) 
Title : Combinatorial principles via a partition theorem for pairs of rational numbersAbstractI will discuss the reverse mathematics and computability theory of the following extension of RT22 (Ramsey's theorem for pairs of natural numbers and two colors): Theorem [Erd\"{o}s, Rado 1952] The partition relation Q \to (\aleph_0, Q)^2 holds. The theorem says that that for every 2coloring f: [Q]^2\to 2 of pairs of rational numbers there exists either an infinite 0homogeneous set or a dense 1homogeneous set. More explicitly, there exists an infinite set A \subseteq Q such that either f\restriction [A]^2=0 or (A, \leq_Q) is dense and f\restriction [A]^2=1. I will also talk about analogs of CAC (Chain AntiChain) and ADS (Ascending Descending Sequence) related to Q \to (\aleph_0, Q)^2. 

16:45  17:30  Hiroshi Sakai (Kobe University) 
Title : On monadic second order theory of $\omega_2$Abstract
