anchor.diff:        homepage = "https://dlmf.nist.gov/LaTeXML/";
         license = lib.licenses.publicDomain;
         maintainers = with maintainers; [ xworld21 ];
  +      mainProgram = "latexml";
       };
       passthru = {
         tlType = "run";
  
positive.code:       homepage = "http://pdl.perl.org/";
        description = "Perl Data Language";
        license = with lib.licenses; [ artistic1 gpl1Plus ];
        platforms = lib.platforms.linux;
      };
    };
  
negative.code:     meta = {
        description = "Manipulates TAR archives";
        license = with lib.licenses; [ artistic1 gpl1Plus ];
        mainProgram = "ptar";
      };
    };
  
  