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| -rw-r--r-- | src/Util/Decidable.v | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/src/Util/Decidable.v b/src/Util/Decidable.v index 3988701a8..e19e23ca4 100644 --- a/src/Util/Decidable.v +++ b/src/Util/Decidable.v @@ -97,6 +97,10 @@ Global Instance dec_eq_nat : DecidableRel (@eq nat) | 10. exact _. Defined. Global Instance dec_eq_N : DecidableRel (@eq N) | 10 := N.eq_dec. Global Instance dec_eq_Z : DecidableRel (@eq Z) | 10 := Z.eq_dec. +Lemma eqsig_eq {T} {U} {Udec:DecidableRel (@eq U)} (f g:T->U) (x x':T) pf pf' : + (exist (fun x => f x = g x) x pf) = (exist (fun x => f x = g x) x' pf') <-> (x = x'). +Proof. apply path_sig_hprop_iff; auto using UIP_dec, Udec. Qed. + Lemma Decidable_respects_iff A B (H : A <-> B) : (Decidable A -> Decidable B) * (Decidable B -> Decidable A). Proof. solve_decidable_transparent. Defined. |