module Eval1;

data Var = Var(Int);

def Bool eq_var(Var v1, Var v2) = v1 == v2;

data Fun = Fun(Int);

def Bool eq_fun(Fun f1, Fun f2) = f1 == f2;

data Exp = Eadd(Exp,Exp)
    | Emult(Exp,Exp)
    | Ediv(Exp, Exp)
    | Econst(Int)
    | Evar(Int, Exp)
    | Elet(Var, Exp, Exp)
    | Eapp(Fun,Exp);

def Int eval(Exp e) =
    case e {
    Eadd(e1,e2) => eval(e1) + eval(e2);
    Emult(e1, e2) => eval(e1) * eval(e2);
    Ediv(e1, e2) => truncate(eval(e1) / eval(e2));
    Econst(n) => n;
};

def Int start(Exp e) = eval(e);

{

}

// let e = Elet(Var 1,Econst 0, Eadd(Econst 1,Econst 1)) in
// eval1 e

//     ;; ()