(a(b(c(de)))) (a(b((cd)e)))
(a (b (c (d e)))) (a (b ((c d) e)))
(a ((b c) (d e))) (a ((b (c d)) e))
(a (((b c) d) e)) ((a b) (c (d e)))
((a b) ((c d) e)) ((a (b c)) (d e))
((a (b (c d))) e) ((a ((b c) d)) e)
((a b) c) (d e)) (((a b) (c d)) e)
(((a (b c)) d) e) ((((a b) c) d) e)