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<div class=Section1>
<p class=MsoNormal><font size=2 color=navy face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial;color:navy'>In short, you should mark
functions and constant parameters with VAR as well. The VAR element marks
its content as incidental, as opposed to elementary functions that do not need
any special markup, like <o:p></o:p></span></font></p>
<p class=MsoNormal align=center style='text-align:center'><code><font size=2
face="Courier New"><span lang=EN-US style='font-size:10.0pt'><SPAN CLASS=</span></font></code><code><font
size=2 face="Courier New"><span style='font-size:10.0pt'>"</span></font></code><code><font
size=2 face="Courier New"><span lang=EN-US style='font-size:10.0pt'>melfun</span></font></code><code><font
size=2 face="Courier New"><span style='font-size:10.0pt'>"</span></font></code><code><font
size=2 face="Courier New"><span lang=EN-US style='font-size:10.0pt'> >sin
<VAR >α</VAR ></SPAN ></span></font></code><code><font
size=2 face="Courier New"><span style='font-size:10.0pt'><o:p></o:p></span></font></code></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial;color:navy'>or <o:p></o:p></span></font></p>
<p class=MsoNormal align=center style='text-align:center'><code><font size=2
face="Courier New"><span lang=EN-US style='font-size:10.0pt'>d<VAR
>x</VAR >² = 2 <VAR >x</VAR > d<VAR
>x</VAR ></span></font></code><code><font size=2 face="Courier New"><span
style='font-size:10.0pt'>.<o:p></o:p></span></font></code></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial;color:navy'>Scalar constants should
be marked with I, as in <o:p></o:p></span></font></p>
<p class=MsoNormal align=center style='text-align:center'><code><font size=2
face="Courier New"><span lang=EN-US style='font-size:10.0pt'><VAR
>S</VAR > = <I >π</I > <VAR >r</VAR >²</span></font></code><code><font
size=2 face="Courier New"><span style='font-size:10.0pt'>.<o:p></o:p></span></font></code></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial;color:navy'>Set constants should be
marked with B, as in <o:p></o:p></span></font></p>
<p class=MsoNormal align=center style='text-align:center'><code><font size=2
face="Courier New"><span lang=EN-US style='font-size:10.0pt'><VAR
>x</VAR > ∈ <B >R</B ></span></font></code><code><font
size=2 face="Courier New"><span style='font-size:10.0pt'>.<o:p></o:p></span></font></code></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial;color:navy'>The VAR element does not
indicate what the underlying text means; it just describes its status as incidental
versus established. Parameters in equations are incidental.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial;color:navy'>Chris<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<div>
<div class=MsoNormal align=center style='text-align:center'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=2 width="100%" align=center tabindex=-1>
</span></font></div>
<p class=MsoNormal><b><font size=2 face=Tahoma><span lang=EN-US
style='font-size:10.0pt;font-family:Tahoma;font-weight:bold'>From:</span></font></b><font
size=2 face=Tahoma><span lang=EN-US style='font-size:10.0pt;font-family:Tahoma'>
whatwg-bounces@lists.whatwg.org [mailto:whatwg-bounces@lists.whatwg.org] <b><span
style='font-weight:bold'>On Be</span></b></span></font><b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma;font-weight:bold'>half
Of </span></font></b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma'>Ozob the Great<br>
<b><span style='font-weight:bold'>Sent:</span></b> Saturday, September 20, 2008
12:42 AM<br>
<b><span style='font-weight:bold'>To:</span></b> whatwg@whatwg.org<br>
<b><span style='font-weight:bold'>Subject:</span></b> [whatwg] Can <var>
possibly work?</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>I am concerned about the existence of HTML5's <var>. This was
brought to my attention during a technical debate on Wikipedia which amounted
to: Where is use of <var> appropriate? The problem is that while
<var> can be used to distinguish variables from non-variables, there are
many other mathematical constructs which cannot properly be called variables.
If variables are going to be distinguished by the markup, then these other
constructs ought be distinguished by the markup. But they can't be put inside <var>
because they're not variables, and furthermore, they can't always said to be
constants, functions, spaces or any short list of allowable objects; the number
of different types of objects occurring in mathematics is tremendous, and
specifying all the allowable objects in HTML markup is undesirable.<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Let me give an elementary example. Consider an equation for a line:<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> y = mx + b.<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>In this equation, only x and y are normally considered variables. m and
b are usually considered constants. So one could mark this up as<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <var>y</var> = m<var>x</var> + b,<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>but then the markup doesn't signal what m and b are though they clearly
have some meaning. One could imagine extending the markup by introducing a
<const> tag:<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <var>y</var> =
<const>m</const><var>x</var> +
<const>b</const>.<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>There are two closely related things to note here. One is that this
must be done manually; an automated tool has no way to distinguish which
symbols are variables and which are constants. The second is that this markup
may be incorrect in some cases (thereby proving the previous point). If one
wants to consider the collection of all lines passing through the point (0, b),
then m becomes a variable, and the markup must change:<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <var>y</var> =
<var>m</var><var>x</var> +
<const>b</const>.<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Conceivably one could make this work for a lot of equations, but
there's at least one more obvious type of object one needs, namely functions.
So one might try to solve this problem by introducing a <funct> tag:<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <funct>f</funct>(<var>x</var>) =
<const>m</const><var>x</var> +
<const>b</const>.<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>As long as one stays within the realm of elementary (precalculus)
mathematics, this might suffice. But modern mathematics has many things which
are not variables, constant numbers, or functions. Even if one interprets
"constant" broadly to mean "constant object" instead of
"constant number" (like it often means), there are still many other
types of objects.<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Content MathML gets around this by defining approximately 120 different
content elements. HTML 5 neither needs nor wants 120 different mathematical
content elements. The only solution I can see to this is to deprecate
<var>: Authors who wish to provide content markup should use MathML,
because it is designed for such things.<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Thoughts?<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>-- <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Ozob<o:p></o:p></span></font></p>
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