a)
$ erlc p001.erl
$ erl
1> p001:solution().b)
$ erl
1> c(p001).
{ok, p001}
2> p001:solution().Install Scheme (Racket)
Downloads Racket from here: http://www.racket-lang.org/
$ ln -s /Applications/Racket v5.2.1/bin/racket /usr/local/bin/racket
$ racket p001.scm