Unique negative dimension

Unique negative dimension (UND) is a complexity measure for the model of learning from positive examples. The unique negative dimension of a class C of concepts is the size of the maximum subclass D ⊆ C such that for every concept c ∈ D , we have ∩ ( D ∖ { c } ) ∖ c is nonempty.

This concept was originally proposed by M. Gereb-Graus in "Complexity of learning from one-side examples", Technical Report TR-20-89, Harvard University Division of Engineering and Applied Science, 1989.