Exact learning of subclasses of CDNF formulas with membership queries

We consider the exact learnability of subclasses of Boolean formulas from membership queries alone. We show how to combine known learning algorithms that use membership and equivalence queries to obtain new learning results only with memberships. In particular we show the exact learnability of read-k monotone formulas, Sat-k O(log n)-CDNF, and O(sqrt{log n})-size CDNF from membership queries only.