2.10 Local Definitions: local
The bindings documented in this section are provided by the racket/local and racket libraries, but not racket/base.
(local [definition ...] body ...+)
Like letrec-syntaxes+values, except that the bindings are
expressed in the same way as in the top-level or in a module body:
using define, define-values, define-syntax,
struct, etc. Definitions are distinguished from
non-definitions by partially expanding definition forms (see
Partial Expansion). As in the top-level or in a module
body, a begin-wrapped sequence is spliced into the sequence
of definitions.