(* Arbre de syntaxe abstraite pour le langage Arith *)

type prg = instr list 
and instr = Set of string*expr | Print of expr
and expr = 
    Cst of int
  | Var of string
  | Op of binop*expr*expr
  | Letin of string*expr*expr
and binop = Sum | Diff | Prod | Quot
;;