8

I would like to produce a new equal symbol looking like this. enter image description here.

What is the best way to do that ? Pure TeX ? TiKz ?

I'm looking for ways to do that rather than to a ready to use solution such as to be able to other new symbols alone.

Davislor
  • 44,045
projetmbc
  • 13,315
  • 2
    This looks to me like Unicode U+2259, estimates (\wedgeq in the stix fonts). What is your intended meaning? (If it's the same. I'll try to add an answer, but since I don't have easy access to a tex system at the moment, including a visual will be difficult.) – barbara beeton Sep 28 '19 at 01:24

3 Answers3

17

Before somebody suggests MnSymbol

\documentclass{article}
\usepackage{amsmath}

\makeatletter
\providecommand{\hateq}{\mathrel{\mathpalette\my@hat@eq\relax}}
\newcommand{\my@hat@eq}[2]{%
  \begingroup
  \sbox\z@{$\m@th#1=$}%
  \ooalign{%
    \hidewidth\raisebox{-0.3\ht\z@}{$\m@th#1\widehat{}$}\hidewidth\cr
    \box\z@\cr
  }%
  \endgroup
}
\makeatother

\begin{document}

$A\cong B\hateq C$                           

\end{document}

enter image description here

With \hat instead of \widehat:

\documentclass{article}
\usepackage{amsmath}

\makeatletter
\providecommand{\hateq}{\mathrel{\mathpalette\my@hat@eq\relax}}
\newcommand{\my@hat@eq}[2]{%
  \begingroup
  \sbox\z@{$\m@th#1=$}%
  \ooalign{%
    \hidewidth\raisebox{-0.2\ht\z@}{$\m@th#1\hat{}$}\hidewidth\cr
    \box\z@\cr
  }%
  \endgroup
}
\makeatother

\begin{document}

$A\cong B\hateq C$

\end{document}

enter image description here

egreg
  • 1,121,712
  • @campa Yes, thanks! – egreg Sep 27 '19 at 15:07
  • How is this different from U+2259, estimates (\wedgeq in the stix fonts)? (I know the shape is slightly different, but what about the meaning?) – barbara beeton Sep 27 '19 at 18:24
  • @barbarabeeton It's the same, I guess. No idea what meaning the OP is assigning to the symbol. – egreg Sep 27 '19 at 20:29
  • This symbol is used to define methods in the B language used to specify and prove programs. – projetmbc Sep 28 '19 at 09:30
  • @barbarabeeton Is there an equivalent of detextify for unicode characters ? – projetmbc Sep 28 '19 at 09:31
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    @projetmbc -- I don't know of any equivalent of detexify for Unicode, but it might be reasonable to make a suggestion to the detexify developer to add Unicode IDs to the returned information. It doesn't look like the stix font info has gotten into detexify, so that's also a plausible request. (The stix font and the addition of many symbols to unicode progressed in tandem.) – barbara beeton Sep 28 '19 at 14:19
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    @barbarabeeton maybe http://shapecatcher.com/? – Rmano Sep 29 '19 at 10:48
  • @Rmano -- Yes, excellent! Thanks. But it doesn't give the TeX names, so I still don't know how to find a symbol (easily) in the comprehensive symbols list unless one already knows the name. – barbara beeton Sep 29 '19 at 12:33
12

What you want could be obtained using

\documentclass[12pt]{article}
\usepackage{amsmath}
\newcommand{\circumeq}{\mathrel{\widehat{=}}}
\begin{document}
\begin{equation*}
a \circumeq b
\end{equation*}
\end{document} 

enter image description here

Denis
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8

The ≙ symbol is U+2259 in Unicode. It has the name \wedgeq in several newer packages, including unicode-math and stix. It is \hateq in two older ones, mnsymbol and fdsymbol. One completely obsolete one, boisik, has \corresponds.

Edit: Sorry, just noticed that Barbara Beeton said that in a comment first. Props!

Davislor
  • 44,045