anchor.diff:    };
   
     fullMaude = fetchurl {
  -    url = "http://maude.cs.uiuc.edu/download/current/FM2.6/full-maude26.maude";
  -    sha256 = "1382hjwwrsdgd5yjn3ph1b5i1bhrhzvqx0v369bmcjkly9k96v6q";
  +    url = "http://maude.lcc.uma.es/FullMaude/FM261e/full-maude.maude.zip";
  +    sha256 = "0g0chfrzc7923sh17zdy731wpsgnwz7rxci0jqqmrphlshwzqm2h";
     };
   
     buildInputs = [flex bison ncurses buddy tecla gmpxx libsigsegv makeWrapper];
  
positive.code: { stdenv, fetchurl, flex, bison, ncurses, buddy, tecla, libsigsegv, gmpxx, makeWrapper }:
  
  stdenv.mkDerivation rec {
    name = "maude-2.6";
  
negative.code:   postInstall = ''
      for n in "$out/bin/"*; do wrapProgram "$n" --suffix MAUDE_LIB ':' "$out/share/maude"; done
      mkdir -p $out/share/maude
      ${unzip}/bin/unzip ${fullMaude} -d $out/share/maude
    '';
  
    meta = {
  