diff options
Diffstat (limited to 'theories')
| -rw-r--r-- | theories/Classes/DecidableClass.v | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/theories/Classes/DecidableClass.v b/theories/Classes/DecidableClass.v index 94fcd55aa5..7169aa673d 100644 --- a/theories/Classes/DecidableClass.v +++ b/theories/Classes/DecidableClass.v @@ -65,6 +65,16 @@ Tactic Notation "decide" constr(P) := Require Import Bool Arith ZArith. +Program Instance Decidable_not {P} `{Decidable P} : Decidable (~ P) := { + Decidable_witness := negb Decidable_witness +}. +Next Obligation. + split; intro Heq. + - apply negb_true_iff in Heq. + eapply Decidable_complete_alt; intuition. + - erewrite Decidable_sound_alt; intuition. +Qed. + Program Instance Decidable_eq_bool : forall (x y : bool), Decidable (eq x y) := { Decidable_witness := Bool.eqb x y }. |