anchor.diff: -{ stdenv, fetchurl, unzip, makeWrapper , flex, bison, ncurses, buddy, tecla
  -, libsigsegv, gmpxx, cln
  +{ stdenv, fetchurl, unzip, makeWrapper, flex, bison, ncurses, buddy, tecla
  +, libsigsegv, gmpxx, cln, yices
   }:
   
   let
   
  -  version = "2.7.1";
  +  version = "3.0";
   
     fullMaude = fetchurl {
  -    url = "http://maude.cs.illinois.edu/w/images/c/ca/Full-Maude-${version}.zip";
  -    sha256 = "0y4gn7n8vh24r24vckhpkd46hb5hqsbrm4w9zr6dz4paafq12fjc";
  +    url = "http://maude.cs.illinois.edu/w/images/0/04/Full-Maude-${version}.zip";
  +    sha256 = "0gf36wlkkl343vlxgryqdhxmgyn8z0cc2zayccd7ac3inmj1iayw";
     };
   
   in
  
positive.code:   postInstall = ''
      for n in "$out/bin/"*; do wrapProgram "$n" --suffix MAUDE_LIB ':' "$out/share/maude"; done
      unzip ${fullMaude}
      install -D -m 444 full-maude.maude $out/share/maude/full-maude.maude
    '';
  
    # bison -dv surface.yy -o surface.c
  
negative.code:       TECLA_LIBS="-ltecla -lncursesw"
        LIBS="-lcln"
        CFLAGS="-O3" CXXFLAGS="-O3"
      )
    '';
  
  