chop is no longer pervasive; removed obsolete thms_containing;
chop is no longer pervasive;
removed obsolete thms_containing;

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