Docs don't agree with behaviour for redefining member/2, memberchk/2.

The docs for member/2 and memberchk/2 say:

This predicate is not protected by ECLiPSe and may be redefined without
generating a warning message.

However:

dog: ~/rotds/stable/bin/i386_linux/eclipse
ECLiPSe Constraint Logic Programming System [kernel]
Copyright Imperial College London and ICL
Certain libraries copyright Parc Technologies Ltd
GMP library copyright Free Software Foundation
Version 5.1.0, Wed Jan 17 11:44 2001
[eclipse 1]: [user].
 memberchk(X,[Y|_]) :- X==Y, !.
 memberchk(X,[_|T]):- memberchk(X,T).
 
*** trying to redefine a built-in predicate: memberchk / 2
        before line 3 in the file user
user       compiled traceable 0 bytes in 0.00 seconds

yes.
[eclipse 2]: 

So either the docs are wrong and should be fixed, or no message should
be generated.

Cheers,
Warwick