;;;;

(define-type seq-basic (or list vector string))
(define-type seq-linear (struct linear-sequence))
(define-type seq-random (struct random-sequence))

(define-type seq (or seq-basic seq-linear seq-random))

(define-type binary-predicate ('a 'a -> boolean))

(define-type binary-equality (* * -> boolean))

;useless since 'a is a "local"
;(define-type accumulator/1 (* 'a -> 'a)

(define-type alist (list-of pair))