Co-NP

In computational complexity theory, co-NP is a complexity class. A decision problem is a member of co-NP if and only if its complement is in the complexity class NP. Instances of decision problems in co-NP are sometimes called "counterexamples". In simple terms, co-NP is the class of problems for which efficiently verifiable proofs of "no" instances exist. Equivalently, co-NP is the set of decision problems where the "no" instances can be solved in polynomial time by a theoretical non-deterministic Turing machine.

Co-NP

In computational complexity theory, co-NP is a complexity class. A decision problem is a member of co-NP if and only if its complement is in the complexity class NP. Instances of decision problems in co-NP are sometimes called "counterexamples". In simple terms, co-NP is the class of problems for which efficiently verifiable proofs of "no" instances exist. Equivalently, co-NP is the set of decision problems where the "no" instances can be solved in polynomial time by a theoretical non-deterministic Turing machine.