Verifiers
A verifier for a language L is an algorithm V, where L={ w | V accepts < w,c > for some string c }
- We measure the time of the verifier in terms of w-- not c, the evidence
- The language L is polynomially verifiable if it has a polytime verifier
NP is the class of languages that have polynomial verifiers
SAT = { Boolean formulas f | f has a satisfying assignment }
CONNECTED = { graphs G | G is connected }
COMPOSITE = { numbers n | n is composite }