CMPT 407/710 - Complexity Theory: Lecture 16
نویسنده
چکیده
The PCP theorem gives a novel characterization of the class NP in terms of probabilistically checkable proofs (PCPs). The central role in this characterization belongs to a Verifier. Here, the probabilities are taken over the random choices of the verifier, and the notation V π means that the verifier V has random access to the string π, i.e., V may request to see the ith bit of the string π, for any i. First, we define some natural restrictions on such verifiers: we restrict the amount of randomness they can use, and the number of queries to the proof they can make. A verifier V is a probabilistic polytime Turing machine with input tape, work tapes, random tape, and random access to a read-only proof string π. We say that a verifier V is (r(n), q(n))-restricted if, on input of size n,
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