Well, yes, I was describing supervised learning (as what doesn't happen) where labels are not present is unsupervised (which makes things much more difficult). Reinforcement is more like a special case between supervised and unsupervised. Difficult like unsupervised because the labels aren't known, but with some feedback that is not a direct answer. Sorry for the confusion. There is very little in the way of purely unsupervised learning. I think the distinction between unsupervised and reinforcement is not very well defined. I would argue that even a "pure" unsupervised algorithm like k-means has a kind of reinforcement in the group means.