Goal:
    a : byte  b : byte  e : NoConfusion_byte a b
  ============================
   (noConfusion_byte_obligation_2 a b (noConfusion_byte_obligation_1 a b e) =
    e)


DEBUG:Going to execute:
fun tac => match goal with
                      | H:?f ?a = ?f' ?a' |- _ => tac H
                      end