fact: Fixpoint finSucc_opt (n : nat) (i : Fin.t n) {struct i} : option (Fin.t n).
imports: Undecidability.TM.Basic.Mono Undecidability.TM.Combinators.Combinators Undecidability.TM.Code.Code Undecidability.TM.Single.EncodeTapes Undecidability.TM.Compound(TMTac MoveToSymbol Multi Shift)