{ stdenv, fetchurl }:
        
stdenv.mkDerivation rec {
  name = "yap-5.1.1";

  src = fetchurl {
    url = "http://downloads.sourceforge.net/yap/Yap-5.1.1.tar.gz";
    sha256 = "0bajxmlla9gay4m4l7y7x6qldxzi0jcq2ykgpjk9liky7g5kbnya";
  };

  meta = { 
    description = "Yap Prolog System is a ISO-compatible high-performance Prolog compiler";
    homepage = http://yap.sourceforge.net/;
    license = "artistic";
  };
}