(*
  LL(1)
  #01 - E0 -> function ident -> E0
  #02 - E0 -> let ident = E0 in E0
  #03 - E0 -> letrec ident = E0 in E0
  #04 - E0 -> if E0 then E0 else E0
  #05 - E0 -> F TY EY EX
  #06 - EX -> = F TY EY EX
  #07 - EX -> 
  #08 - EY -> + F TY EY
  #09 - EY -> - F TY EY
  #10 - EY -> 
  #11 - TY -> * F TY
  #12 - TY -> / F TY
  #13 - TY -> 
  #14 - F  -> - F
  #15 - F  -> ( E0 ) FX
  #16 - F  -> ident FI
  #17 - F  -> true
  #18 - F  -> false
  #19 - F  -> number
  #20 - FX -> ( E0 )
  #21 - FX -> 
  #22 - FI -> ( EO )
  #23 - FI -> 
*)