CASE
====

syntax: (case <keyform> {({<key> |
              ({<key> ...})} {<form> ...}) ...})

case is a conditional that chooses one of its clauses
to execute by comparing a value to various constants,
which are typically keyword symbols, integers, or
characters (but may be any objects).

example:       >(case 1 (3 'c)
                        (2 'b)
                        (1 'a)
                        (t 'end))
               A