5.3.4

6 Typed Racket Syntax Without Type Checking

 #lang typed/racket/no-check
 #lang typed/racket/base/no-check

On occasions where the Typed Racket syntax is useful, but actual typechecking is not desired, the typed/racket/no-check and typed/racket/base/no-check languages are useful. They provide the same bindings and syntax as typed/racket and typed/racket/base, but do no type checking.

Examples:

#lang typed/racket/no-check
(: x Number)
(define x "not-a-number")