#! /usr/local/bin/guile -s
!#

(define upper 
	(lambda ()
		(begin (display "upper") (newline))))

(define lower
	(lambda ()
		(begin (display "lower") (newline))))

(define zero
	(lambda ()
		(begin (display "zero") (newline))))

(define sign 
	(lambda (number)
	(cond   ((> number 0)  (upper) )
		((< number 0)  (lower) )
		(else 000  (zero) ))))

(sign 10)
;
(sign -10)
;
(sign 0)
;