GPLed; improved begin_theory: proper presentation if 'files' change theory;
GPLed;
improved begin_theory: proper presentation if 'files' change theory;

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