removed obsolete rev_contrapos (cf. 1d195de59497);
removed obsolete rev_contrapos (cf. 1d195de59497);

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