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What is the proof of P ⊆ NP? I cannot happen to find a good explanation for it. I read that the
verifier will just ignore the proof and accept any proof if the solution is YES and reject all proofs if the answer is NO. I'm also unclear about verifier.
Definition of P and NP I follow:
P: a problem 'Q' is said to be in P if there exists an efficient (polynomial worst-case time) algorithm for solving the problem. E.g.- "is a given natural number 'x' even?".
NP: a problem 'Q' is said to be in NP if there exists efficient verifiers (an algorithm for verifying if a given proof is correct).