DynamicHelp & canvas tags

[Mike Ignatoski]

I have a Tkx app, and I'm using the DynamicHelp BWidget for canvas
items.  The balloon help works fine, except that I can only get it to
work for items identified using a single tag.  I cannot get it to work
for 'tag expressions'.
 
I'm trying this:
 
  Tkx::DynamicHelp__add ( $canvas, -item=> 'this_tag && !that_tag', ...
 
Is there a different syntax for this situation?
 
Thanks,
Mike