On 22/09/2011 22:44, Bruno Le Floch wrote:
>> What it seems is needed is an interface that makes sense, i.e. which
>> separates out:
>> 1) The general interline penalty
>> 2) The penalty for lines(s) at the start of the paragraph as a whole
>> 3) The penalty for lines(s) at the end of the paragraph as a whole
>> 4) The penalty for line(s) before display math
>> 5) The penalty for line(s) after display math
>> 6) Additional penalties between arbitrary lines
>> or some such structure. This will require a bit of thought, as it means
>> synchronising the various primitives in an ordered way.
> I'm afraid (3) doesn't exist (not sure). It would be
> \the\interlinepenalties <length>-k, where <length> is the number of
> lines in the paragraph.
No, \widowpenalties applies only at the end of the paragraph as a whole,
not at the end of the partial paragraph. The \widowpenalties and
\displaywidowpenalties cover cases (3) and (4) in a clear manner
(additivity, of course, with \interlinepenalt(y|ies).
I have an overall idea now on what is needed!