Knuth is simply defining a piecewise function here in ordinary math notation. Functional programming languages borrow heavily from math, Erlang is a functional language. The resemblance would probably be even more striking with Haskell... which only serves to undermine the message.
Erlang's great though. Glad to see some irrational exuberance for it.
Erlang's great though. Glad to see some irrational exuberance for it.