✐‹creator "Kevin Kappelmann"› subsubsection ‹Substitution› theory Zippy_Instance_Subst imports Zippy_Instance_Hom_Changed_Goals_Data begin setup‹Context.theory_map ML_Gen.ground_zipper_types› ML_file‹zippy_instance_subst_data.ML› setup‹Context.theory_map ML_Gen.reset_zipper_types› end