This is a programmer's lambda-calculus pun.
(λf.((λx.xx)
(λr.f(rr)))) is an important but
somewhat-controversial combinator.
It's often written in expanded form, and with the Latin character "L" in place of the Greek lambda, 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 the pun :)