anchor.diff:        "${pkgs.ghostscript}/share/ghostscript/fonts"
       ];
     };
  -  
  +
   }
  
positive.code:       includes = map (x: [x.key (baseNameOf (toString x.key))])
          (findLhs2TeXIncludes {rootFile = source;});
      };
    
    animateDot = dotGraph: nrFrames: pkgs.stdenv.mkDerivation {
      name = "dot-frames";
      builder = ./animatedot.sh;
  
negative.code:       inherit postscript;
  
        buildInputs = [pkgs.imagemagick pkgs.ghostscript];
  
        buildCommand = ''
          if test -d $postscript; then
            input=$(ls $postscript/*.ps)
  