+(define-system s1 ()
+ (entities-changes
+ (list (new-entity (make-a 1 2))
+ (new-entity (make-a 10 20)))))
+
+(define-system s2 ((with-a (a)))
+ (for-each
+ (lambda (e)
+ (format #t "Key: ~a Component: ~a~%" (get-key e) (get-component 'a e)))
+ with-a))
+