IPPSPACE
IPPSPACE is a complexity-theoretic class defined in the area of interactive proofs. It refers to languages that admit an interactive proof system in which the verifier is restricted to polynomial space (PSPACE) in the input length. In such a system, a computationally unbounded prover interacts with the PSPACE-bounded verifier to convince the verifier that a given string belongs to the language. The standard completeness and soundness requirements apply: for strings in the language there exists a prover strategy that makes the verifier accept with high probability, and for strings not in the language no prover strategy can force acceptance with probability beyond a specified bound.
The resource constraint on the verifier is central: the verifier’s work is limited to polynomial space, and
Relationship to other classes varies with definitions. It is straightforward to see that PSPACE ⊆ IPPSPACE, since
Examples of PSPACE-complete problems, such as TQBF, are encompassed by IPPSPACE. See also interactive proofs, PSPACE,