I've taken to defining "@" as the Y combinator, so it looks kind of like a "goto" label for looping, e.g.: (@\fact\n \n==n <= n 0 1 (* n (fact (- n 1)))) (T

I've taken to defining "@" as the Y combinator, so it looks kind of like a "goto" label for looping, e.g.: (@\fact\n \n==n <= n 0 1 (* n (fact (- n 1)))) (The \n==n forces an eager evaluation, to avoid building a tower of deferred operations with large n.) The symbol "fact" is arbitrary, e.g. you could say this instead: (@\loop\n \n==n <= n 0 1 (* n (loop (- n 1)))) To define a name "fact" for that function, it's: \fact = (@\loop\n \n==n <= n 0 1 (* n (loop (- n 1))))