\accent primitive (as in ‘syst\‘eme’)
just as much as the exclamation in‘syst!eme’.
(Hyphenation takes place on the characters “sent to the printer”.
The problem with \accent is avoided —in LaTeX — by the use
of the fontenc package, as discussed in
“Accented words aren t hyphenated”.)
Sets of hyphenation patterns are usually derived from analysis of
a list of valid hyphenations (the process of derivation, using a tool
called patgen, is not ordinarily a sport to be played by
ordinary mortals).
The patterns for the languages a TeX system is going to deal with
may only be loaded when the system is installed. To change the set of
hyphenation patterns recognised by a TeX-based or XeTeX system,
a partial reinstallation is necessary (note that
LuaTeX relaxes this constraint).
TeX provides two “user-level” commands for control of
hyphenation: \language (which selects a hyphenation style), and
\hyphenation (which gives explicit instructions to the hyphenation
engine, overriding the effect of the patterns).
The ordinary LaTeX user need not worry about \language, since
it is very thoroughly managed by the babel package; use of
\hyphenation is discussed in
the context of
hyphenation failure.
This answer last edited: 2012-12-03
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