2.23 Flattening Syntactic Sequences: nest
The bindings documented in this section are provided by the scheme/nest and scheme libraries, but not scheme/base.
Combines nested expressions that syntactically drift to the right into
a more linear textual format, much in the same way that let*
linearizes a sequence of nested let expressions.
is equivalent to
The nest form is unusual in that it has no semantics apart
from its expansion, and its implementation is easier to understand
than a precise prose description: