Re: [Groff] A progress report

[Ted Harding]

On 07-Feb-07 Eric S. Raymond wrote:
> Ted Harding <address@hidden>:
>>                                   As you can see,
>> the lineup does its job, despite the intervening text. (And
>> it carries over past page-breaks too).
>> 
>> I don't see how this is compatible  with your description
>> of troff "treating multiple adjacent .EQ/.EN spans as a
>> single display"? Maybe it does work like that if the EQ/EN
>> blocks are adjacent, as in your example; but there must be
>> some other mechanism there when they are not (as in mine).
> 
> You're right.  I explained the situation poorly.  The respect in which
> eqn treats these as adjacent displays is just that it remembers mark
> and lineup locations after an EQ/EN span has been processed.
> Intervening text doesn't matter.
> 
> I guess I should have said that all EQ/EN spans are treated as a single
> display for mark/lineup purposes, because that's how it works
> internally.

Yes, that's now clear!

> MathML doesn't have this behavior,  When you have multiple MathML 
> markup spans in a document, later ones know nothing about earlier ones;
> <alignmark> information is forgotten at the closing </math> tag.
> 
> To do the nearest equivalent in MathML, all the displays that want to
> share alignment state have to be wrapped in a top-level table element.

I don't know enough about MathML to guess whether this may be
a silly suggestion, but I wonder whether it's possible to emulate
the 'eqn' mechanism in MathML?

I.e., can one set a "global variable2 in MathML? Where, in this
case, it would have the value of the offset at the "mark" point,
and be called on for setting offsets at subsequent "lineups"?
(This is basically how eqn does it, I think).

Ted.

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Date: 07-Feb-07                                       Time: 21:22:06
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