NSPACE is a concept from complexity theory, a branch of theoretical computer science.

There NSPACE ( f) stands for the space complexity class of decision problems that ( f) can be solved by a non -deterministic Turing machine with space O. It is the non-deterministic counterpart to DSPACE. NSPACE (f ( n ) ) is closed under complement ( set of Immerman and Szelepcsényi ).

With NSPACE other complexity classes are often defined. As can be inferred from NPSPACE NSPACE as follows: