[LON-CAPA-users] Chemistry again - equilibrium symbol

[Guy Albertelli II]

Hi Mark,

> Matt is fishing around for an option for the symbol for equilibrium under 
> html.
> 
> Is there an html equivalent to \rightleftharpoon in tex?

No, but there is a unicode equivalent so if you have UTF-8 encoded
document you can use the unicode symbol reference ⇌

(I am pretty sure IE 6's unicode font set doesn't include this
particular symbol.)

In Lon-CAPA's chemparse we do:
 if ($external::target eq 'web' && &EXT('request.browser.unicode')) {
     $formula .= '⇌ ';
 } else {
     $formula .= &web('<=>','<m>\ensuremath{\rightleftharpoons}</m> ',
		      '&lt;=&gt;');
 }

which mean, if it's a unicode capable brower output the &#8652;

Otherwise in html do <=> and in text do <m>\ensuremath{\rightleftharpoons}</m> 

BTW here is the unicode set of arrows:
http://www.unicode.org/charts/PDF/U2190.pdf

-- 
guy@albertelli.com  LON-CAPA Developer  0-7-2-6-