In common-lisp how is the relation between types defined?
(subtypep 'string '(array character)) ==> NIL, T
(subtypep '(array character) 'string) ==> NIL, T

(typep (make-string x) '(array character)) ==> T
(typep (make-array x :element-type :character) 'string) ==>T

ccl e$ rlwrap ./dx86cl64
Loading ~/ccl-init.lisp
Welcome to Clozure Common Lisp Version 1.7-dev-r14614M-trunk  (DarwinX8664)!
? (subtypep 'string '(array character))
T
T
?

(subtypep 'base-string 'array) => T
(subtypep 'base-string '(array base-char)) => T
(subtypep 'string 'array) => T
(subtypep 'string '(array character)) => NIL
(subtypep 'string '(array base-char)) => NIL
(subtypep 'string '(array standard-char)) => NIL
(subtypep 'string '(array extended-char)) => NIL

(subtypep '(vector nil) 'string)