proper proof context transfer wrt. background theory avoids ad-hoc restore operation
proper proof context transfer wrt. background theory avoids ad-hoc restore operation

MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle