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<div class="moz-cite-prefix">On 10/29/2022 1:31 PM, Gabriel Tellez
via Unicode wrote:<br>
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<blockquote type="cite"
cite="mid:CALpKH7oHiJQe5D5JUu1m84_k=4veyAVJaUYfOFrOkT1dCtOc2g@mail.gmail.com">
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<div dir="auto">Looks like the real answer (hopefully) would be if
we could find out what U+207B SUPERSCRIPT MINUS was originally
added for.</div>
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<p>These characters were in Unicode from very early on. Unlike some
of the later additions there is no link to a particular citation
"in the wild". Instead, the original repertoire collected a
superset of then existing character sets in reasonably wide usage.
If any of their members violated Unicode encoding principles, they
were added as compatibility characters (to facilitate round trip),
otherwise as ordinary characters.</p>
<p>However, the question implicitly supposes that symbols and
punctuation are encoded by function. That is not generally
correct. They are encoded based on distinct (contrasting) shape
compared to other symbols (noting that for dashes and similar
symbols, shape is not only defined by the "ink" but also where
that "ink" is placed). If a symbol was reused for something else
without a change in appearance, it would not therefore qualify for
being re-encoded.</p>
<p>In this case, the appearance of SUPERSCRIPT MINUS in a modern
math font shows a relative positioning to superscript digits, full
sized digits and relative length to the standard minus sign that
matches to the TI character for negation (within the constrained
imposed by limited resolution raster images).</p>
<p>I can see no indication that the TI engineers had some other
symbol in mind, that is had they had the choice of a
Unicode-encoded outline font, they would have chosen something
with an appearance very distinct from SUPERSCRIPT MINUS. Unless
and until someone can come up with a very cogent argument that
they were really trying to model something that is visually
distinct from a superscript minus sign, there is no reason to
reject that mapping.</p>
<p>However, as I pointed out in another message, we should reject a
mapping to 203E even though some sources have it: the visuals
simply do not match.<br>
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