[tex-hyphen] hyphenation with ligatures in input

[Arthur Reutenauer]

>> input shouldn't contain such ligatures and if it does, it might be with a purpose
> 
> I cannot agree with the first part of that statement, although I do with
> the second.

  You should.  Characters such as U+FB01 are deprecated and shouldn't be
used in text.

>                                            any character that is
> in the Unicode character set must be valid in an input document.

  It is valid.  It just doesn't mean what you think.

> It may well be that TeX-based engines that use Unicode will have
> to evolve further to handle the complexities that will undoubtedly
> arise.

  In many areas, yes.  In this particular case though, users have to be
educated not to use the legacy ligatures from Unicode in their documents
-- and in many cases, programmers have to be educated to this effect,
too.

	Arthur