Definition proj_sumbool_is_false : forall (P : Prop) (a : {P} + {~ P}), ~ P -> Coqlib.proj_sumbool a = false.
Module BlockList.
Fixpoint mkBlockList (n : nat) : list nat :=
match n with
| 0 => nil
| S 0 => nil
| S n =>  n :: (mkBlockList n)
end.

Lemma mkBlockList_include : forall n k (Hk: k > 0) (Hineq: k < n) (Hn: n > 1),
List.In k (mkBlockList n).