Trees and languages

2. How to define boolean's set in F# ?
3. (match_with)
   How to define standard booleans' operators (not, and, etc.) ?

type Bool = True | False;;

let Not b = 
  match b with
  | True  -> False
  | False -> True;;

let And b1 b2 = 
  match b1 with
  | True  -> b2
  | _     -> False;;

not False;;
And True (Not False);;

let (<&>) b1 b2 = And b1 b2;;
True <&> (Not False);;

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