Largest families without an r-fork. Order-a Journal on the Theory of Ordered Sets and Its Applications. 2007;24:181-97.
Largest family without A boolean OR B subset of C boolean AND D. Journal of Combinatorial Theory Series A. 2005;111(2):331-6. Abstract
Largest family without A boolean OR B subset of C boolean AND D
Let F be a family of subsets of an n-element set not containing four distinct members such that A boolean OR B subset of C boolean AND D. It is proved that the maximum size of F under this condition is equal to the sum of the two largest binomial coefficients of order n. The maximum families are also characterized. A LYM-type inequality for such families is given, too. (c) 2005 Elsevier Inc. All rights reserved.