12 lines
123 B
Racket
12 lines
123 B
Racket
#lang typed/scheme
|
|
|
|
|
|
|
|
(define-type (T+ elem)
|
|
(U (A elem)))
|
|
|
|
(define-type (T elem)
|
|
(U T+ 2))
|
|
|
|
(define-struct: (x) A ())
|