updated magic_history docstring

IPython/core/history.py

@@ -717,9 +717,7 b' def _format_lineno(session, line):'
 def magic_history(self, parameter_s = ''):
     """Print input history (_i<n> variables), with most recent last.
 
-    %history       -> print at most 40 inputs (some may be multi-line)\\
-    %history n     -> print at most n inputs\\
-    %history n1 n2 -> print inputs between n1 and n2 (n2 not included)\\
+    %history       -> prints all history from this session
 
     By default, input history is printed without line numbers so it can be
     directly pasted into an editor. Use -n to show them.
@@ -772,9 +770,10 b" def magic_history(self, parameter_s = ''):"
     --------
     ::
 
-      In [6]: %hist -n 4 6
+      In [6]: %hist -n 4-6
       4:a = 12
       5:print a**2
+      6:%hist -n 4-6
 
     """