…I hope this finds you and your dear wife well.  Please give my regards to Anne and Bill and our other friends at the Institute.

Yours truly,

Alvin

P.S. I forgot to mention: I have been working on a new mathematical theory of the universe of multiple dimensions.  I had an idea about applying the lambda calculus to the problem we were discussing over sherry that last evening—do you remember?  I can’t wait to show you.

P.P.S. Now it just struck me: if the human mind is, as I think, capable of holding these generating formulas in tension then interdimensional travel should be possible.  Who knows what strange and exotic dimensions we might enter using one of the many universe generators.  Query: are there infinitely many such alternate universes, as I guess? Countably infinite, or uncountably?  Must consider this.

P.P.P.S.  I’m sure this could work!  One simply holds the generating formula for an alternate universe in the mind; one imagines applying the Y-combinator, and then—there you are, Q.E.D.!  For example, if I take the ?4 generator we discussed and hold it firmly in my mind, and then concentrate on applying the Y-combinator, like this, then I should