Spelling errors fixed.

doc/Protocol-A.texi

@@ -1227,7 +1227,7 @@ called ``Protocol B'', and at one point in time it was believed that
 19'' arrived and was obsoleted by new versions.  Meanwhile, it was
 discovered that ``Protocol A'' was more extensible that first
 believed.  ``Protocol A'' will continue to evolve, but it is unlikely
-that it will ever be superceded by ``Protocol B''.}.
+that it will ever be superseded by ``Protocol B''.}.
 
 The protocol version letter should be
 followed by connection information required by that protocol.  In
@@ -4519,7 +4519,7 @@ anyway.
                 -> ( @lt{Text-List} );
 @end example
 
-This call has been superceded by @reqlink{local-to-global}.
+This call has been superseded by @reqlink{local-to-global}.
 
 This call retrieves an array mapping local text numbers to global
 numbers.  It is most often used to get a list of unread texts in a
@@ -4651,7 +4651,7 @@ This call returns the @type{Info-Old} structure for the server
 (@pxref{Info-Old}).  Clients should call this in order to find
 out which conferences are used for presentations and such.
 
-This call has been superceded by @reqlink{get-info}.
+This call has been superseded by @reqlink{get-info}.
 
 This call can be issued without logging in.
 
@@ -7647,7 +7647,7 @@ This message is sent when a text is created.  The text number of the text
 is sent in @aarg{text-no} and the text stat in @aarg{text-stat}.  This
 message is sent to all logged-in members of any recipient of the text.
 
-In protocol version 10 this call has been superceded by @ref{async-new-text}.
+In protocol version 10 this call has been superseded by @ref{async-new-text}.
 
 
 
@@ -7791,7 +7791,7 @@ logging in is sent in @aarg{pers-no}, and the session number in
                                 message   :   @lt{HOLLERITH} ));
 @end example
 
-This message has been superceded by @asyncdlink{async-send-message} which
+This message has been superseded by @asyncdlink{async-send-message} which
 is more flexible@linkhere{}.  It used to be sent when the administrator
 (@aarg{sender}) broadcasted a string (@aarg{message}) to all LysKOM
 users, but is no longer used.