The expand-defmacro procedure takes a single (quoted)
expression and expands all macros in the expression. The
expand-defmacro-once procedure is similar: it expands
macros, but does not try to expand the result of an expansion. Only
the syntactic forms shown in Figure 3.1 will occur in a
fully expanded expression.
A
cond will appear only with zero clauses, and only in an optional
mode where the exn:else exception is raised if no clause matches (see
section 2.10).
Figure 3.1: Syntactic forms after expanding with expand-defmacro