Did I miss one of Asimov's Robot novels?

I finished I, Robot, Caves of Steel, and The Naked Sun, and now I’ve just started The Robots of Dawn. The first several chapters keep referring to a third meeting between Elijah and Daneel, involving two mathematicians. Did this even happen in some other publicized work of Asimov’s, or is it something that will be explained later in the book (please attempt to answer without spoilers, if you can…)