Added tree-find.
Added tree-find.

GitoriousLispBackup/com-informatimago,GitoriousLispBackup/com-informatimago,informatimago/lisp,informatimago/lisp,GitoriousLispBackup/com-informatimago,informatimago/lisp,informatimago/lisp,GitoriousLispBackup/com-informatimago,informatimago/lisp,informatimago/lisp,GitoriousLispBackup/com-informatimago,informatimago/lisp,GitoriousLispBackup/com-informatimago