X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Focaml%2Fmathql_interpreter%2FmQIExecute.ml;h=2f5ca7eb69e76d2e7ba28d7c138eab94519fb0ea;hb=6e67bd83fc8e1465bfdb7fcd4cd8eef9c9350b45;hp=7bd7bd8b9645bf1381ddb486cfcc661fd3c07d08;hpb=48b9bb5e9504aba97cff28a9d7e2797feb42972e;p=helm.git

diff --git a/helm/ocaml/mathql_interpreter/mQIExecute.ml b/helm/ocaml/mathql_interpreter/mQIExecute.ml
index 7bd7bd8b9..2f5ca7eb6 100644
--- a/helm/ocaml/mathql_interpreter/mQIExecute.ml
+++ b/helm/ocaml/mathql_interpreter/mQIExecute.ml
@@ -232,9 +232,10 @@ let execute out m x =
 	 let keep_av (s, g) = (s, List.fold_right keep_set g []) in
 	 List.map keep_av (eval_query c x) 
    and eval_grp c = function
-      | M.Attr l ->
+      | M.Attr gs ->
          let attr_aux g (p, y) = U.mql_union g [(p, eval_val c y)] in
-	 [List.fold_left attr_aux [] l]
+	 let attr_auxs s l = U.set_union s [List.fold_left attr_aux [] l] in
+	 List.fold_left attr_auxs [] gs
       | M.From i ->
          try snd (List.assoc i c.avars) 
 	 with Not_found -> warn (M.AVar i); []