proposition: Lemma MoveToSymbol_Step_true t x : current t = Some x -> f x = true -> MoveToSymbol_Step_Fun t = tape_write t (Some (g x)).
proof: Proof. intros H1 H2. unfold MoveToSymbol_Step_Fun. destruct t; cbn in *; inv H1. rewrite H2. auto. Qed.
imports: Undecidability(TM.Util.Prelim) Undecidability(TM.Basic.Mono) Undecidability(TM.Combinators.Combinators) Undecidability(TM.Compound.TMTac) Undecidability(TM.Compound.Multi) Coq(FunInd) Coq(Recdef)