tuned USEDIR_OPTIONS; PDF_VIEWER: try to be smart for MacOS (Darwin);
tuned USEDIR_OPTIONS;
PDF_VIEWER: try to be smart for MacOS (Darwin);

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