## Main Assumption

**In this talk**, *A* is an *N**P*-predicate, that is:

*y*∈*A*(*x*, _) can be tested in*polynomial time*.*y*is of size*polynomial*in the size of*x*.

Many natural problems have this property:

- Enumerate the
*answer set*of a**database query***Q*on database 𝔻 - Enumerate the
*transversals*of a**hypergraph ℋ**