sad: fix build

pkgs/applications/science/logic/sad/default.nix

@@ -7,7 +7,12 @@ stdenv.mkDerivation {
     sha256 = "10jd93xgarik7xwys5lq7fx4vqp7c0yg1gfin9cqfch1k1v8ap4b";
   };
   buildInputs = [ ghc spass ];
-  patches = [ ./patch ];
+  patches = [
+    ./patch
+    # Since the LTS 12.0 update, <> is an operator in Prelude, colliding with
+    # the <> operator with a different meaning defined by this package
+    ./monoid.patch
+  ];
   postPatch = ''
     substituteInPlace Alice/Main.hs --replace init.opt $out/init.opt
     '';
@@ -23,7 +28,7 @@ stdenv.mkDerivation {
   meta = {
     description = "A program for automated proving of mathematical texts";
     longDescription = ''
-      The system for automated deduction is intended for automated processing of formal mathematical texts 
+      The system for automated deduction is intended for automated processing of formal mathematical texts
       written in a special language called ForTheL (FORmal THEory Language) or in a traditional first-order language
       '';
     license = stdenv.lib.licenses.gpl3Plus;