**Class ENP** (an extension of class NP coNP)

is in *ENP* if ,
(certificate) with which the correctness of output
can be verified in time polynomial in both the input size |*x*| and
the output size.

**Proposition.** EP ENP.

**Conjecture.** EP ENP.

Wed Jun 12 17:26:21 GMT+0100 1996