[plt-scheme] Tip on indenting requested

try

 > (pretty-print '(and (=> (and (and (and (or (and (= char_encoded|s3 
True) (= g108091
?)) (and (= char_encoded|s3 False) (= g108092 ?)))) (and (or (and (=
char_absorbed|s3 True) (= g108097 ?)) (and (= char_absorbed|s3 False)
(= g108098 ?)))))) (and (or (and (= current_char|s3 a) (=
decoded_char|s3 a)) (and (= current_char|s3 e) (= decoded_char|s3 e))
(and (= current_char|s3 i) (= decoded_char|s3 i)) (and (=
current_char|s3 o) (= decoded_char|s3 o)) (and (= current_char|s3 u)
(= decoded_char|s3 u)))))))

gives

(and (=>
      (and (and (and (or (and (= |char_encodeds3 True) (= g108091
?)) (and (= char_encodeds3| False) (= g108092 ?))))
                (and (or (and (=
                               |char_absorbeds3 True) (= g108097 ?)) 
(and (= char_absorbeds3|
                               False)
                              (= g108098 ?))))))
      (and (or (and (= |current_chars3 a) (=
decoded_chars3| a))
               (and (= |current_chars3 e) (= decoded_chars3| e))
               (and (= |current_chars3 i) (= decoded_chars3| i))
               (and (= |current_chars3 o) (= decoded_chars3| o))
               (and (= |current_chars3 u)
(= decoded_chars3| u))))))