(* * Copying Machines and Helper functions for verifying machines using [CopySymbols] ane [MoveToSymbol] *)
From Undecidability Require Export TM.Compound.CopySymbols TM.Compound.MoveToSymbol.
Local Generalizable All Variables.
Set Default Proof Using "Type".
(* Don't simplify [skipn (S n) xs]; only, if the number and the lists are constructors *)
Local Arguments skipn { A } !n !l.
Local Arguments plus : simpl never.
Local Arguments mult : simpl never.
Variable f : sig -> sig.

Corollary CopySymbols_L_steps_moveleft ls ls' x m rs :
stop x = true ->
CopySymbols_L_steps stop (tape_move_left' (ls ++ x :: ls') m rs) <= 8 + 8 * length ls.