You don't have to use any of the syntax if you don't want to. You can write directly in KLambda. Here's how `map` is defined in KLambda:

   (defun map (f l)
     (shen.map-h f l ()))

   (defun shen.map-h (f l accum)
     (cond ((= () l) (reverse accum))
           ((cons? l) (shen.map-h f (tl l) (cons (f (hd l)) accum)))
           (true (shen.f_error shen.map-h))))