anchor.diff:        TECLA_LIBS="-ltecla -lncursesw"
         LIBS="-lcln"
         CFLAGS="-O3" CXXFLAGS="-O3"
  -      --without-cvc4    # Our version is too new for Maude to cope.
       )
     '';
   
  
positive.code: { stdenv, fetchurl, unzip, makeWrapper , flex, bison, ncurses, buddy, tecla
  , libsigsegv, gmpxx, cln
  }:
  
  let
  
    version = "2.7.1";
  
    fullMaude = fetchurl {
      url = "http://maude.cs.illinois.edu/w/images/c/ca/Full-Maude-${version}.zip";
      sha256 = "0y4gn7n8vh24r24vckhpkd46hb5hqsbrm4w9zr6dz4paafq12fjc";
    };
  
  in
  
negative.code:   meta = {
      homepage = http://maude.cs.illinois.edu/;
      description = "High-level specification language";
      license = stdenv.lib.licenses.gpl2Plus;
  
      longDescription = ''
        Maude is a high-performance reflective language and system
  