fact: Definition atStart (t : tape sigSim) (tps : list (tape sig)) : Prop := t = midtape nil (inl START) (map inr (encode_list (@encode_tape sig) tps) ++ [inl STOP]).
imports: Undecidability.TM.Basic.Mono Undecidability.TM.Combinators.Combinators Undecidability.TM.Code.Code Undecidability.TM.Single.EncodeTapes Undecidability.TM.Compound(TMTac MoveToSymbol Multi Shift)