anchor.diff:      let
         dsfmt_ver = "2.2";
         grisu_ver = "1.1.1";
  -      utf8proc_ver = "1.1.6";
   
         dsfmt_src = fetchurl {
           url = "http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/SFMT/dSFMT-src-${dsfmt_ver}.tar.gz";
  
positive.code: { stdenv, fetchgit, gfortran, perl, m4, llvm, gmp, pcre, zlib
  , readline, fftwSinglePrec, fftw, libunwind, suitesparse, glpk, fetchurl
  , ncurses, libunistring, patchelf, openblas, arpack
  , tcl, tk, xproto, libX11, git, mpfr, which
  }:
  
  with stdenv.lib;
  
negative.code:       "LIBLAPACKNAME=libopenblas"
  
        "USE_SYSTEM_ARPACK=1"
  
        "USE_SYSTEM_UTF8PROC=1"
      ];
  
    GLPK_PREFIX = "${glpk}/include";
  