anchor.diff:      inherit (param) rev sha256;
     };
   
  -  buildInputs = with coq.ocamlPackages; [ ocaml camlp5 findlib ];
  -  propagatedBuildInputs = [ coq ssreflect ];
  +  buildInputs = [ coq ]
  +  ++ (with coq.ocamlPackages; [ ocaml camlp5 findlib ])
  +  ++ (param.buildInputs or [])
  +  ;
  +  propagatedBuildInputs = [ ssreflect ] ++ (param.propagatedBuildInputs or []);
   
     enableParallelBuilding = false;
  +
  +  preConfigure = param.preConfigure or null;
   
     installPhase = ''
       make -f Makefile.coq COQLIB=$out/lib/coq/${coq.coq-version}/ install
  
positive.code:       rev = "195e550a1cf0810497734356437a1720ebb6d744";
        sha256 = "0zm23y89z0h4iamy74qk9qi2pz2cj3ga6ygav0w79n0qyqwhxcq1";
      };
    };
    param = params."${coq.coq-version}";
  in
  
negative.code: { stdenv, fetchFromGitHub, coq, ssreflect, coq-ext-lib, simple-io }:
  
  let params =
    {
  