This is a programmer's lambda-calculus pun.
(Lf.((Lx.xx) (Lr.f(rr)))) is an important but
somewhat-controversial combinator. It's often written as:
(Lf.((Lx.f(xx)) (Lx.f(xx))))
That form should be googlable. It
also has a single-letter name that works, phonetically, with the
rest of my .signature :)