http://trac.sacrideo.us/wg/wiki/BracketsBraces shows the meaning
of square brackets and curly braces in my Scheme test suite, which
currently includes 45 implementations.  Only Chibi and RScheme currently
do something special with braces; the other implementations treat them
as either synonyms for parentheses, lexical syntax errors, or identifier
characters.

--
A rose by any other name                            John Cowan
may smell as sweet,                                 http://www.ccil.org/~cowan
but if you called it an onion                       xxxxxx@ccil.org
you'd get cooks very confused.          --RMS