Doc Variable and Apply node correctly (for Variable.eval)

doc/library/gof/graph.txt

+.. _libdoc_gof_graph:
+
+==============================================
+:mod:`graph` -- Interface for the Theano graph
+==============================================
+
+.. module:: graph
+   :platform: Unix, Windows
+   :synopsis: Interface for types of symbolic variables
+.. moduleauthor:: LISA
+
+---------
+Reference
+---------
+
+.. automodule:: theano.gof.graph
+    :members:

doc/library/gof/index.txt

@@ -13,6 +13,7 @@
 .. toctree::
     :maxdepth: 1
 
+    graph
     fgraph
     toolbox
     type

doc/library/gof/type.txt

@@ -4,7 +4,7 @@
 :mod:`type` -- Interface for types of variables
 ================================================
 
-.. module:: fgraph
+.. module:: type
    :platform: Unix, Windows
    :synopsis: Interface for types of symbolic variables
 .. moduleauthor:: LISA

doc/tutorial/adding.txt

@@ -117,7 +117,8 @@ then be used like a normal Python function.
 .. note::
 
     As a shortcut, you can skip step 3, and just use a variable's
-    :func:`eval` method. The :func:`eval` method is not as flexible
+    :func:`eval <theano.gof.graph.Variable.eval>` method.
+    The :func:`eval` method is not as flexible
     as :func:`function` but it can do everything we've covered in
     the tutorial so far. It has the added benefit of not requiring
     you to import :func:`function` . Here is how :func:`eval` works:

theano/gof/graph.py

@@ -451,6 +451,31 @@ class Variable(Node):
         inputs_to_values
             A dictionary mapping theano Variables to values.
 
+        Examples
+        --------
+
+        >>> import theano.tensor as T
+        >>> x = T.dscalar('x')
+        >>> y = T.dscalar('y')
+        >>> z = x + y
+        >>> z.eval({x : 16.3, y : 12.1})
+        array(28.4)
+
+        We passed :func:`eval` a dictionary mapping symbolic theano
+        variables to the values to substitute for them, and it returned
+        the numerical value of the expression.
+
+        Notes
+        -----
+
+        `eval` will be slow the first time you call it on a variable --
+        it needs to call :func:`function` to compile the expression behind
+        the scenes. Subsequent calls to :func:`eval` on that same variable
+        will be fast, because the variable caches the compiled function.
+
+        This way of computing have more overhead then a normal Theano
+        function, so don't use it too much in real script. But is
+        useful for interactive session and quick experiments.
         """
 
         if inputs_to_values is None: