<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> </head> <body><div class="auto-created-dir-div" dir="auto" style="unicode-bidi: embed;"><style>p{margin:0}</style>Interestingly, many years ago Bernard Miller, in his Bytext proposal, suggested what he termed "arrow parentheses".<div><p><br></p><p>There were eight of them.</p><p><br></p><p>The glyphs were each either an opening or closing parenthesis character, with either one or two up arrows, or one or two down arrows upon the parenthesis.</p><p><br></p><p>The single ones opened or closed a sequence of characters that were to be subscript or superscript, the double ones were for limits of definite integrals, summations and so on.</p><p><br></p><p>It seemed to me then, and does so now, to be a very good idea.</p><p><br></p><p>I am not an expert on Unicode and maybe there is some structural reason why this could not become implemented, even if people wanted it implemented.</p><p><br></p><p>Yet I put this forward in the hope that the idea will be considered seriously please.</p><p><br></p><p>https://www.unicode.org/mail-arch/unicode-ml/y2002-m01/0477.hl<br></p><p><br></p><p>Here is a link to The Bytext Standard document.</p><p><br></p><p>https://web.archive.org/web/20030317065850/http://bytext.org/The_Bytext_Standard.pdf<br></p><p><br></p><p>Arrow parentheses are on pages 33 and 34.</p><p><br></p><p>Oh, and notwithstanding the comments about Bytext made in the mailing list thread at the time, please have a look at pages 37 and 38 and observe what was being suggested in 2002. Hmm.</p><p><br></p><p><span style="display: inline !important;">William Overington</span></p><p><span style="display: inline !important;"><br></span></p><p>Thursday 3 June 2021</p><p><br></p><br><blockquote style="margin: 0 auto; padding: 0 2em; border-left:2px solid #00ADE5; white-space: pre-wrap "><br><br>------ Original Message ------<br>From: "Don Peterson via Unicode" <unicode@corp.unicode.org><br>To: unicode@corp.unicode.org<br>Sent: Thursday, 2021 Jun 3 At 19:29<br>Subject: Suggestion for superscripts<br><br><div dir="ltr"><div>For about a decade I have been wanting to be able to print Unicode superscript characters in the output of some programs. The most common use case for this is to print the exponents to physical units. An example is kg·m/s², which is a bit easier on the eyes and brain than kg*m/s**2. </div><div><br></div><div>Unfortunately, the current version 13 character set doesn't have enough superscript characters to support common scientific usage. From the ucd.nounihan.grouped XML file for version 13, these are the superscript and subscript characters I could find:<br></div><div><br></div><div>Superscripts: ⁰ ¹ ² ³ ⁴ ⁵ ⁶ ⁷ ⁸ ⁹ ⁺ ⁻ ⁼ ⁽ ⁾ ⁱ ⁿ<br>Subscripts: ₀ ₁ ₂ ₃ ₄ ₅ ₆ ₇ ₈ ₉ ₊ ₋ ₌ ₍ ₎ ₐₑₕᵢⱼₖₗₘₙₒₚᵣₛₜᵤᵥₓᵦᵩ</div><div><br></div><div>Superscript characters are lacking for two fairly common use cases: floating point exponents and fractional exponents. These would be possible with the addition to the superscripts of the two common radix characters '.' and ',' and a solidus character. However, it seems to me that <b>the Unicode design should aim at least at putting all printable 7-bit ASCII characters and the upper and lower case Greek characters commonly used in technical work in both the subscript and superscript sets</b>. I've never commented on this before because I thought it was obvious and would be fixed in the next Unicode revision. I remember looking at this pretty carefully around version 7 and being surprised by the lack. Being a lazy retired person for the last 20 years meant I didn't do anything about it, which I now regret. :^)<br></div><div><br></div><div>Because of this lack of superscript characters, one of my library functions is forced to produce syntactically-correct but ugly output such as <span style="font-family: monospace;">m**0.75·Pa**-1.3·s⁻²·K⁻¹ </span>for a units string input of "<span style="font-family: monospace;">m(3/4) Pa(-1.3)/(s2*K)</span>" (with syntax similar to the GNU units program). <br></div></div> </blockquote></div></div></body></html>