fact: Fixpoint gamma (A : stack nat) := match A with | [] => [] | (x, y) :: A => gamma A ++ x ++ [#] ++ y ++ [#] end.
imports: List Lia Undecidability.CFG.CFP Undecidability.CFG.Util.Facts Undecidability.PCP.PCP Undecidability.PCP.Util.Facts Undecidability.PCP.Util.PCP_facts Undecidability.Synthetic.Definitions