RE: The mapping of phi

Sure.  I think most of us understand about Unicode.  

But since the whole point of having two code points is that the difference between a straight phi and a curly phi carries semantic meaning in mathematics, it doesn't really help the reader if the 03C6 sitting there in the DOM is unambiguously declared to be the phi symbol character by Unicode when what the reader actually sees on the screen randomly switches between the straight and curly glyphs depending on the font.  

Having spent far more of my life than I want to debugging phi problems in publishing workflows, I can assure you it is a real world problem, even if the theoretical foundation is clear.


Dr. Robert Miner
W3C Math Working Group co-chair
Vice President, Research and Development
Design Science, Inc.
140 Pine Avenue, 4th Floor
Long Beach, California 90802
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> -----Original Message-----
> From: [] On
> Behalf Of Elliotte Harold
> Sent: Wednesday, April 02, 2008 9:33 AM
> To: Neil Soiffer
> Cc:;
> Subject: Re: The mapping of phi
> Neil Soiffer wrote:
> > That even sort of applies if you use the Unicode value for the
> > character.  Because Unicode changed the glyph associated with the
> code,
> > any font that was developed and not updated before that change has
> the
> > wrong character at the &phi and &phiv positions.
> I'm sorry. What happened?!
> This makes no sense at all. Unicode does not define *any* glyphs for
> *any* characters, and never has. It maps abstract characters to code
> points. That's all. What glyph is used for those characters is a font
> choice. Unicode cannot change a glyph becuase it never assigned a glyph
> in the first place.
> I suppose different printings of various books may use different fonts,
> but this is in no way normative.
> > So, depending upon the
> > font, the glyph for 3c5 may be a GREEK SMALL LETTER PHI (an "open"
> curly
> > phi) or GREEK PHI SYMBOL (a "straight" phi).  See [7] for more
> details.
> >
> Possibly, but none of this changes the fact that υ is the Greek
> small letter upsilon. I suppose you meant φ ? In Unicode that's
> the small Greek letter phi, whatever glyph is assigned.
> --
> Elliotte Rusty Harold
> Java I/O 2nd Edition Just Published!


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Received on Wednesday, 2 April 2008 15:00:40 UTC