anchor.diff:        version of the simplex algorithm.
       '';
   
  -    homepage = http://www.cs.unipr.it/ppl/;
  -
  -    license = "GPLv3+";
  -
       maintainers = [ stdenv.lib.maintainers.ludo ];
     };
   }
  
positive.code:   enableParallelBuilding = true;
  
    meta = {
      description = "PPL: The Parma Polyhedra Library";
  
      longDescription = ''
        The Parma Polyhedra Library (PPL) provides numerical abstractions
  
negative.code: { fetchurl, stdenv, gmpxx, perl, gnum4 }:
  
  let version = "0.12.1"; in
  
  stdenv.mkDerivation rec {
    name = "ppl-${version}";
  
    src = fetchurl {
      url = "http://bugseng.com/products/ppl/download/ftp/releases/${version}/ppl-${version}.tar.bz2";
      sha256 = "165iy8bmkgszs0v8lkb1mzwp53x4vkcc7m1xdpv8w77qf93ya8j0";
    };
  
    nativeBuildInputs = [ perl gnum4 ];
  