Partition subalgebras for maximal almost disjoint families Original Research Article

Partitioner algebras are defined by Baumgartner and Weese (Trans. Amer. Math. Soc. 274 (2) (1982) 619) as a natural tool for studying the properties of maximal almost disjoint families of subsets of ω. We prove from PFA+ and ♢(S02) that there exists a partitioner algebra which contains a subalgebra which is not representable as a partitioner algebra.