 If we want a better match with our intuitions, we must demand more from a compositional language than the mere existence of a function from structures and the meanings of parts to the meanings of wholes. One possibility would be to put constraints on this function—we could demand, for example that it be computable, or perhaps even that the computation be reasonably quick. But the above example shows that such a strengthening would not solve the problem: if computing the meanings of complex expressions is easy in English, it will not be hard in Crypto-English either. We might instead opt for the following strengthening of  (C):