Introducing potential sorting flag
diff --git a/src/main/java/de/ids_mannheim/korap/query/wrap/SpanAttributeQueryWrapper.java b/src/main/java/de/ids_mannheim/korap/query/wrap/SpanAttributeQueryWrapper.java
index c21a968..52e2036 100644
--- a/src/main/java/de/ids_mannheim/korap/query/wrap/SpanAttributeQueryWrapper.java
+++ b/src/main/java/de/ids_mannheim/korap/query/wrap/SpanAttributeQueryWrapper.java
@@ -15,8 +15,11 @@
         this.subquery = sqw;
         if (!inclusion) {
             this.isNegation = true;
-        }
-    }
+        };
+
+        if (sqw.maybeUnsorted())
+            this.maybeUnsorted = true;
+    };
 
     @Override
     public SpanQuery toQuery() throws QueryException {