goops noob issues

% guile --version
guile (GNU Guile) 2.1.0

% guile
(use-modules (oop goops describe))

(define-class <complex-n> (<number>) r i)
(define c1 (make <complex-n> 1 1))
(describe c1)
;; ->
;; #<<complex-n> 93d8510> is an instance of class <complex-n>
;; Slots are:
;;      r = #<unbound>
;;      i = #<unbound>