fix a typo

dkrenn · dkrenn · commit 41874bafbd0f · 2016-08-22T14:56:23.000+02:00
diff --git a/src/sage/combinat/recognizable_series.py b/src/sage/combinat/recognizable_series.py
@@ -22,7 +22,7 @@
 
 .. WARNING::
 
-    As this code is experimental, warnings are thrown when a a
+    As this code is experimental, warnings are thrown when a
     recognizable series space is created for the first time in a
     session (see :class:`sage.misc.superseded.experimental`).
 
