On the wikipedia article about the polynomial hierarchy http://en.wikipedia.org/wiki/Polynomial_hierarchy
it says "$A^B$ is the set of decision problems solvable by a Turing machine in class A augmented by an oracle for some complete problem in class B"
What is a "Turing machine in class A" for classes P, NP, and coNP?
I'm guessing a Turing machine in P is a deterministic Turing machine that can only run for polynomial time in the size of its input
and that a Turing machine in NP is a nondeterministic Turing machine that can only run for polynomial time in the size of its input
But I have no clue what is a Turing machine in class coNP ?