Definition Qeval_nformula :=
  eval_nformula 0 Qplus Qmult  Qeq Qle Qlt (fun x => x) .Definition Qeval_op1 (o : Op1) : Q -> Prop :=
match o with
| Equal => fun x : Q => x == 0
| NonEqual => fun x : Q => ~ x == 0
| Strict => fun x : Q => 0 < x
| NonStrict => fun x : Q => 0 <= x
end.

Lemma Qeval_nformula_dec : forall env d, (Qeval_nformula env d) \/ ~ (Qeval_nformula env d).