(defun f(s)(if(=(setf c(read-char)a(char-int c))10)(#1=format t"~:[yes~;failed at: EOL~]
"s)(if(find c"(<{[")(f`(,a,@s))(if(< 0(- a(pop s))3)(f s)(#1#t"failed at: ~C~A
"c(read-line))))))(loop(f()))
Note that non-ascii characters in the above source code will be escaped (such as \x9f).