anchor.diff:  
   let
     pname = "alt-ergo";
  -  version = "2.3.2";
  +  version = "2.3.3";
   
     src = fetchurl {
       url = "https://alt-ergo.ocamlpro.com/http/alt-ergo-${version}/alt-ergo-${version}.tar.gz";
  -    sha256 = "130hisjzkaslygipdaaqib92spzx9rapsd45dbh5ssczjn5qnhb9";
  +    sha256 = "124k2a4ikk4wdpmvgjpgl97x9skvr9qznk8m68dzsynzpv6yksaj";
     };
  -
  -  preConfigure = "patchShebangs ./configure";
   
     nativeBuildInputs = [ which ];
   
  
positive.code: 
  let alt-ergo-lib = ocamlPackages.buildDunePackage rec {
    pname = "alt-ergo-lib";
    inherit version src preConfigure nativeBuildInputs;
    configureFlags = pname;
    propagatedBuildInputs = with ocamlPackages; [ num ocplib-simplex stdlib-shims zarith ];
  }; in
  
  let alt-ergo-parsers = ocamlPackages.buildDunePackage rec {
    pname = "alt-ergo-parsers";
    inherit version src preConfigure nativeBuildInputs;
    configureFlags = pname;
    buildInputs = with ocamlPackages; [ menhir ];
    propagatedBuildInputs = [ alt-ergo-lib ] ++ (with ocamlPackages; [ camlzip psmt2-frontend ]);
  
negative.code: 
  ocamlPackages.buildDunePackage {
  
    inherit pname version src nativeBuildInputs;
  
    configureFlags = pname;
  
  