Ernest, the smallest learning artificial agent in the world

Ernest can only do two things: A or B.
Ernest can only perceive two things: "Yee" or "o-o". That is good, because those are the only two things that his environment can exhibit.
Ernest loves Yees and hates o-os. Will he learn that, in this environment, to get Yees, one must do B?
The answer is in his activity trace. Play it with your speakers on, because Ernest speaks!!
So, Ernest finds his happiness by exploiting the simplest possible regularity in his environment: A makes o-o and B makes Yee.
But what happens if his environment exhibits more complex regularities? That is what we have to study next.