fact: Definition to_fin_MP : T.selector unit := (fun l=> let n := mlength l in M.mapi (fun i '(m: _, g) => H <- prove_leq i n; let v := rcbv (of_nat_lt H) in T.open_and_apply (T.exact v) g) l;; M.ret [m:])%MC.
imports: Mtac2.Mtac2 Vector Lia