;; program.scm

(declare (uses foobar))

(module main ()

(import chicken scheme)
(import foobar)

(display (fac 10))
(newline)

)

;; foobar.scm

(declare (unit foobar))

(module foobar *

(import chicken scheme)

(define (fac n)
  (if (zero? n)
    1
    (* n (sub1 n))))

)

;; $ csc -s foobar.scm -j foobar
;; $ csc -s foobar.import.scm
;; $ csc program.scm foobar.scm
;; $ ./program