If you're maximizing over all possible values of W, A never changes, which is why the /P(A) will usually be omitted from the function you're maximizing. You're

If you're maximizing over all possible values of W, A never changes, which is why the /P(A) will usually be omitted from the function you're maximizing. You're right, though, it shouldn't be written as P(W|A) in that case, that's misleading.