 Grice’s Determinacy condition states that S conversationally implicates p only if S has to believe (and implicate) p if S’s utterance is to be consistent with the Cooperative Principle. Determinacy is a key premise in the working-out schema, so Calculability depends on it. As  §8  illustrated, however, there are normally many alternative ways to be cooperative, and contribute what is required by the conversation, even when the meanings and referents of the words used are taken as given.