anchor.diff:  
     ### SCIENCE
   
  -  celestia = callPackage ../applications/science/astronomy/celestia {
  -    lua = lua5_1;
  -    inherit (xlibs) libXmu;
  -    inherit (pkgs.gnome) gtkglext;
  -  };
  -
  -  xplanet = callPackage ../applications/science/astronomy/xplanet { };
  -
  -  gravit = callPackage ../applications/science/astronomy/gravit { };
  -
  -  spyder = callPackage ../applications/science/spyder {
  -    inherit (pythonPackages) pyflakes rope sphinx numpy scipy matplotlib; # recommended
  -    inherit (pythonPackages) ipython pep8; # optional
  -    inherit pylint;
  -  };
  -
  -  stellarium = callPackage ../applications/science/astronomy/stellarium { };
  -
  -
     ### SCIENCE/GEOMETRY
   
     drgeo = builderDefsPackage (import ../applications/science/geometry/drgeo) {
  
positive.code: 
    eukleides = callPackage ../applications/science/math/eukleides { };
  
    gap = callPackage ../applications/science/math/gap { };
  
    maxima = callPackage ../applications/science/math/maxima { };
  
negative.code: 
    boinc = callPackage ../applications/science/misc/boinc { };
  
    celestia = callPackage ../applications/science/astronomy/celestia {
      lua = lua5_1;
      inherit (xlibs) libXmu;
      inherit (pkgs.gnome) gtkglext;
    };
  
    gravit = callPackage ../applications/science/astronomy/gravit { };
  
    golly = callPackage ../applications/science/misc/golly { };
  
    root = callPackage ../applications/science/misc/root { };
  
    simgrid = callPackage ../applications/science/misc/simgrid { };
  
    spyder = callPackage ../applications/science/spyder {
      inherit (pythonPackages) pyflakes rope sphinx numpy scipy matplotlib; # recommended
      inherit (pythonPackages) ipython pep8; # optional
      inherit pylint;
    };
  
    stellarium = callPackage ../applications/science/astronomy/stellarium { };
  
    tulip = callPackage ../applications/science/misc/tulip { };
  
    vite = callPackage ../applications/science/misc/vite { };
  
    xplanet = callPackage ../applications/science/astronomy/xplanet { };
  
    ### MISC
  
  