return sets instead of tuples from some symtable methods
diff --git a/Doc/library/symtable.rst b/Doc/library/symtable.rst
index ee24823..4bb59e8 100644
--- a/Doc/library/symtable.rst
+++ b/Doc/library/symtable.rst
@@ -95,19 +95,19 @@
.. method:: get_parameters()
- Return a tuple containing names of parameters to this function.
+ Return a set containing names of parameters to this function.
.. method:: get_locals()
- Return a tuple containing names of locals in this function.
+ Return a set containing names of locals in this function.
.. method:: get_globals()
- Return a tuple containing names of globals in this function.
+ Return a set containing names of globals in this function.
.. method:: get_frees()
- Return a tuple containing names of free variables in this function.
+ Return a set containing names of free variables in this function.
.. class:: Class
@@ -116,7 +116,7 @@
.. method:: get_methods()
- Return a tuple containing the names of methods declared in the class.
+ Return a set containing the names of methods declared in the class.
.. class:: Symbol