A level is a lexical property of an identifier that determines in which
phases it can be referenced.

In the absence of a definition of what it means to "reference" an
identifier (despite a formal comment by me on this precise point, asking for
clarification, that was ignored), and whether literal uses count as
identifiers, the interpretation assumed by the expander in Larceny is just
as valid as any other. Thus, since Larceny gives an exception, it follows that
the code in question is not R6RS compliant.

Andre