Re: Combining markup

Hi Paul,

> But isn't this a good cause for most MathML-presentation 
> implementations to provide no (or a poor) sub-term selection mechanism?
> While in my copy-and-paste explorations, I could see little done in the 
> area of sub-term selection.

This is a good point, but I'm not sure which is cause and which

> As I understand it, parallel markup is required if one wants to offer 
> correct sub-term selection (i.e. a selection mechanism where the 2+3 is 
> highlighted when the mouse as dragged over "2+").

At some level, this is obviously true, since a software package that
is going to deal with sub-term selection is going to track the
relation between the content markup in the source and the presentation
markup it is displaying.  But the exact selection behavior is somewhat
independent.  In WebEQ we chose to allow one to select the 2+, but if
you copy it to the clipboard, you will just get the corresponding
presentation fragment.  If you select the entire 2+3, then you will
get the corresponding content markup, since there is a correspondence
at that level.  We could have done it differently, of course, but the
choice isn't really a function of the markup.

The obvious exception is that if you, the author, want _control_ over
the subterm selection by changing the source, then parallel markup of
some sort is going to be necessary.


Dr. Robert Miner                      
W3C Math Interest Group Co-Chair                      651-223-2883
Design Science, Inc.   "How Science Communicates"

Received on Monday, 19 April 2004 13:44:00 UTC