A Mad Q-set
Abstract
A MAD (maximal almost disjoint) family is an infinite subset A of the infinite subsets of 0,1,2,.. such that any two elements of A intersect in a finite set and every infinite subset of 0.1.2... meets some element of in an infinite set. A Q-set is an uncountable set of reals such that every subset is a relative G-delta set. It is shown that it is relatively consistent with ZFC that there exists a MAD family which is also a Q-set in the topology in inherits a subset of the Power set of 0,1,2,.., ie the Cantor set.
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