Trac #21295 review issue 7: document accessing coefficients

Author: dkrenn

src/sage/combinat/recognizable_series.py

@@ -313,10 +313,17 @@ def __init__(self, parent, mu, left, right):
         EXAMPLES::
 
             sage: Rec = RecognizableSeriesSpace(ZZ, [0, 1])
-            sage: Rec((Matrix([[3, 6], [0, 1]]), Matrix([[0, -6], [1, 5]])),
-            ....:     vector([0, 1]), vector([1, 0])).transposed()
+            sage: S = Rec((Matrix([[3, 6], [0, 1]]), Matrix([[0, -6], [1, 5]])),
+            ....:         vector([0, 1]), vector([1, 0])).transposed(); S
             [1] + 3*[01] + [10] + 5*[11] + 9*[001] + 3*[010] + ...
 
+        We can access coefficients by
+        ::
+
+            sage: W = Rec.indices()
+            sage: S[W([0, 0, 1])]
+            9
+
         .. SEEALSO::
 
             :doc:`recognizable series <recognizable_series>`,