Fix a typo

Author: kwankyu

src/sage/game_theory/normal_form_game.py

@@ -1137,7 +1137,7 @@ def _gambit_(self, as_integer=False, maximization=True):
             { "" 3, 5, 8 }
             { "" 2, 6, 4 }
             }
-            1 2 3 4 5 6 7 8 
+            1 2 3 4 5 6 7 8
             <BLANKLINE>
         """
         from decimal import Decimal

src/sage/graphs/domination.py

@@ -513,7 +513,7 @@ def _aux_with_rep(H, to_dom, u_next):
 
         .. WARNING::
 
-            The same output may be output several times (up to ``H`` times).
+            The same output may be output several times (up to `|H|` times).
 
         In order to later remove duplicates, we here output pairs ``(ext, i)``
         where ``ext`` is the output candidate extension and ``i`` counts how
@@ -593,7 +593,7 @@ def minimal_dominating_sets(G, to_dominate=None, work_on_copy=True):
     - ``work_on_copy`` -- boolean (default: ``True``); whether or not to work on
       a copy of the input graph; if set to ``False``, the input graph will be
       modified (relabeled).
-    
+
     OUTPUT:
 
     An iterator over the inclusion-minimal sets of vertices of ``G``.