[OS X TeX] ligaturess

[cfrees at imapmail.org]

On Sat 17th Jul, 2010 at 21:16, Jonathan Kew seems to have written:

> On 17 Jul 2010, at 20:51, Dr. Clea F. Rees wrote:
>
>> If I typeset the following:
>> ---ligature test file---
>> % !TEX TS-program = pdflatex
>> % !TEX encoding = UTF-8 Unicode
>> \listfiles
>> \documentclass[12pt]{article}
>> \title{Brief Article}
>> \author{The Author}
>>
>> \begin{document}
>>
>> f{}f ff shelf{}ful f{}f ff\\
>>
>> \end{document}
>> ---end test file---
>> then I get (what is to me) unexpected output.
>>
>> Expected:
>> no-lig-ff lig-ff shel-no-lig-ff-ul no-lig-ff lig-ff
>>
>> Actual:
>> no-lig-ff lig-ff shel-lig-ff-ul no-lig-ff lig-ff
>>
>> Why does TeX ignore the instruction not to use the ff ligature in
>> 'shelful' when a line break occurs afterwards? And why does it
>> nonetheless accept the instruction if the f-no-lig-f is typeset in
>> isolation?
>
> Because it attempted hyphenation, while looking for (and failing to find) a better way to line-break the paragraph.
>
> {} is not a reliable way to prevent a ligature. Use {\kern0pt} or possibly \/. See The TeXbook, p.306.

Thank you. (I should probably look at The TeXbook sometime...)

So the compwordmark gets discarded as part of attempting hyphenation?
Interesting.

- cfr