diff --git a/prelude/sets.v b/prelude/sets.v index e92b14e6f635e8bec8fc5f4d043f01bc6a756616..758915bcd929be15b52945adb13af176b184cb5e 100644 --- a/prelude/sets.v +++ b/prelude/sets.v @@ -18,6 +18,9 @@ Instance set_difference {A} : Difference (set A) := λ X1 X2, Instance set_collection : Collection A (set A). Proof. by split; [split | |]; repeat intro. Qed. +Lemma mkSet_elem_of {A} (f : A → Prop) x : f x → x ∈ mkSet f. +Proof. done. Qed. + Instance set_ret : MRet set := λ A (x : A), {[ x ]}. Instance set_bind : MBind set := λ A B (f : A → set B) (X : set A), mkSet (λ b, ∃ a, b ∈ f a ∧ a ∈ X).