;; Compilation:
;;   csc -O4 -block -c foo.scm
;;   csc -O4 -block -c main.scm
;;   csc -O4 -block main.o foo.o

;; main.scm

(declare (uses foo))
(main)

;; foo.scm

(declare (unit foo))

(define (main)
  (display "FOO!")
  (newline)
  #f)