typos

* spot/twaalgos/alternation.hh: Typos.
* spot/twa/twa.hh: Typos.

spot/twa/twa.hh

@@ -947,7 +947,7 @@ namespace spot
 
     /// \brief Set generalized Büchi acceptance
     ///
-    /// \param num the number of acceptance sets to used
+    /// \param num the number of acceptance sets to use
     ///
     /// The acceptance formula of the form
     /// \code
@@ -969,8 +969,8 @@ namespace spot
     /// acceptance.  The returned mark \c {0} can be used to tag
     /// accepting transition.
     ///
-    /// Note that this does not make the automaton as using
-    /// state-based acceptance.  If you want to create a Büchi
+    /// Note that this does not mark the automaton as using
+    /// state-based acceptance. If you want to create a Büchi
     /// automaton with state-based acceptance, call
     /// \code
     /// prop_state_acc(true)

spot/twaalgos/alternation.hh

@@ -27,7 +27,7 @@ namespace spot
   /// \brief Helper class combine outgoing edges in alternating
   /// automata
   ///
-  /// The idea is that you can the operator() on some state to get an
+  /// The idea is that you can call the operator() on some state to get an
   /// BDD representation of its outgoing edges (labels and
   /// destinations, but not acceptance marks).  The BDD representation
   /// of different states can combined using & or | to build a new
@@ -65,6 +65,7 @@ namespace spot
   /// Acceptance marks are dropped.
   ///
   /// The results is very likely to be alternating.
+  /// @}
   template<class I>
   SPOT_API
   unsigned states_and(const twa_graph_ptr& aut, I begin, I end)
@@ -97,6 +98,7 @@ namespace spot
   /// acceptance is only used in presence of size-1 rejecting-SCCs.)
   ///
   /// \param named_states name each state for easier debugging
+  /// @}
   SPOT_API
   twa_graph_ptr remove_alternation(const const_twa_graph_ptr& aut,
                                    bool named_states = false);