[tex-hyphen] hyphenation with ligatures in input

[Philip Taylor]

Arthur Reutenauer wrote:

>   In American English "Xnancial" is hyphenated as "X-nan-cial".  In
> British English it's hyphenated as "Xn-an-cial". 

Because of the patterns, or because of \LHM & \RHM ?
** Phil.