Definition dist_inh {X} (d : dist X) : X.

(* Specifications: *)
Lemma Q_of_nat_nz (n : nat) : n <> 0%nat -> ~ Q_of_nat n == 0.
Lemma dist_card_nz {X} `{Finite X} (d : dist X) :
~ Q_of_nat (card X) == 0.