Unique negative dimension
Unique negative dimension is a complexity measure for the model of learning from positive examples.
The unique negative dimension of a class of concepts is the size of the maximum subclass such that for every concept, we have 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.