Abstract (Benjamin Sudakov)

Let S = { (A_i,B_i) | 1 <= i <= m } be a set system such that |A_i|=a, |B_i|=b and, for all i,j, A_i and B_j are disjoint if and only if i=j. B. Bolobas proved that the size of S is at most (a+b) choose b. We will discuss applications of this result and its generalizations to extremal set theory.

Last modified: January 8, 1996.

Kim Skak Larsen (kslarsen@imada.sdu.dk)