[Tex/LaTex] n equal sign with wider gap

Question

I am trying to make a large unary operator from an equal sign =, namely, \mathlarger{\boldsymbol{=}}, but the bars are too close together to distinguish from the general binary case. Is there some package with = having a wider gap that I can use?

Answer 1

Here's a proposal:

\documentclass{article}
\usepackage{amsmath,xparse}

\ExplSyntaxOn
\NewDocumentCommand{\uneq}{}
 {
  \mathbin{\mathpalette\updraft_uneq:nn {}}
 }

\dim_new:N \l__updraft_width_dim
\dim_new:N \l__updraft_height_dim

\cs_new_protected:Nn \updraft_uneq:nn
 {
  \vcenter
   {
    \mathsurround=0pt
    \hbox:n
     {
      % measure the width of the equals sign in the current style
      \hbox_set:Nn \l_tmpa_box {$#1{=}$}
      \dim_set:Nn \l__updraft_width_dim { \box_wd:N \l_tmpa_box }
      % measure the width of 1mu in the current style
      \hbox_set:Nn \l_tmpa_box {$#1\mkern1mu$}
      \dim_set:Nn \l__updraft_height_dim { \box_wd:N \l_tmpa_box }
      % start drawing
      \driver_draw_begin:
      % round caps on lines
      \driver_draw_cap_round:
      % set the line width (change 1.2 to your liking)
      \driver_draw_linewidth:n { 1.2\l__updraft_height_dim }
      % 1. cm fonts use width/10  of side bearings
      % 2. the gap between lines is 5 times the line width
      % bottom line
      \driver_draw_moveto:nn
       { 0.1 \l__updraft_width_dim }
       { -2.5 \l__updraft_height_dim }
      \driver_draw_lineto:nn
       { 0.9 \l__updraft_width_dim }
       { -2.5 \l__updraft_height_dim }
      \driver_draw_stroke:
      % top line
      \driver_draw_moveto:nn
       { 0.1 \l__updraft_width_dim }
       { 2.5 \l__updraft_height_dim }
      \driver_draw_lineto:nn
       { 0.9 \l__updraft_width_dim }
       { 2.5 \l__updraft_height_dim }
      \driver_draw_stroke:
      \driver_draw_end:
      % occupy the space
      \hspace{ \l__updraft_width_dim }
     }
   }
 }
\ExplSyntaxOff

\begin{document}

$\mathbin{=}A$

$\uneq A$ $\scriptstyle\uneq A$ $\scriptscriptstyle\uneq A$

$A=B$

\end{document}

There is no “unary operator” class, one has to use \mathbin and TeX will act according to the context. You could also decide to simply use \mathord.