anchor.diff:            license = lib.licenses.free;
           };
         }) {};
  +    sweeprolog = callPackage ({ elpaBuild, emacs, fetchurl, lib }:
  +      elpaBuild {
  +        pname = "sweeprolog";
  +        ename = "sweeprolog";
  +        version = "0.4.5";
  +        src = fetchurl {
  +          url = "https://elpa.nongnu.org/nongnu/sweeprolog-0.4.5.tar";
  +          sha256 = "17dbrn2yvc6ib4dig410kbmvpwp4iz6q9hx6g0mk3vxqjrmgwyls";
  +        };
  +        packageRequires = [ emacs ];
  +        meta = {
  +          homepage = "https://elpa.gnu.org/packages/sweeprolog.html";
  +          license = lib.licenses.free;
  +        };
  +      }) {};
       swift-mode = callPackage ({ elpaBuild, emacs, fetchurl, lib, seq }:
         elpaBuild {
           pname = "swift-mode";
  
positive.code:       elpaBuild {
          pname = "helm";
          ename = "helm";
          version = "3.8.7";
          src = fetchurl {
            url = "https://elpa.nongnu.org/nongnu/helm-3.8.7.tar";
            sha256 = "1n0m061amrzm0xpgqy2mp9vrk2960gqhl5hi6c1smcmm7nxqwz12";
          };
          packageRequires = [ helm-core popup ];
          meta = {
  
negative.code:       elpaBuild {
          pname = "annotate";
          ename = "annotate";
          version = "1.8.0";
          src = fetchurl {
            url = "https://elpa.nongnu.org/nongnu/annotate-1.8.0.tar";
            sha256 = "169cav480g2fm3z7d5dixrng2h8fv39sa9n066b79cb573p4bbcp";
          };
          packageRequires = [];
          meta = {
  