anchor.diff: -{ stdenv, fetchurl, flex, bison, ncurses, buddy, tecla, libsigsegv, gmpxx, makeWrapper, unzip }:
  +{ stdenv, fetchurl, flex, bison, ncurses, buddy, tecla, libsigsegv, gmpxx, makeWrapper }:
   
   stdenv.mkDerivation rec {
     name = "maude-2.6";
  
positive.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 = {
  
negative.code:   };
  
    fullMaude = fetchurl {
      url = "https://full-maude.googlecode.com/git/full-maude261h.maude";
      sha256 = "0xx8bfn6arsa75m5vhp5lmpazgfw230ssq33h9vifswlvzzc81ha";
    };
  
    buildInputs = [flex bison ncurses buddy tecla gmpxx libsigsegv makeWrapper];
  