This is a very short question and hopefully there's a short answer. I know I can use \stackrel{top}{bot} to vertically merge two symbols into one with top on top and bot on the bottom. Is there something similar for left-right merging? I ask because I want to make a += symbol (for an additive update step in code). If there's already a symbol for that, that would be OK too.
[Tex/LaTex] How to horizontally merge two symbols
symbols
Related Solutions
This is a clear case for \accentset from the accents package:
\documentclass{article}
\usepackage{accents}
\newcommand{\vect}[1]{\accentset{\rightharpoonup}{#1}}
\begin{document}
$\vect{x}$
\end{document}
RE-REVISED SOLUTION (to make CENTERS of asterisks match CENTERS of \ddag):
This revised solution allows flexibility to specify the gap between the asterisks, which will necessarily shrink them accordingly. In this MWE, I place 0pt, 3pt, and 6pt, respectively, between the cropped asterisks (and half that again above and below them), before \scalerel'ing them to the exact vertical dimensions of the cropped \ddag. The only subjective aspect to the solution is \cropast and \cropddag in which the user must crop the extra space surrounding the asterisk and double-daggar, using \addvbuffer. But the nice thing with this approach is that, if you change fonts, one merely needs to rework the crop in the new font, and the rest of the solution follows directly from that, unaltered. I show that feature below, with this code:
\documentclass{article}
\usepackage{stackengine}
\usepackage{verbatimbox}
\usepackage{scalerel}
\parindent 0in
%%%%%%%%%%%%%%%%%%%%%%%%%%
\def\cropast{\addvbuffer[-0.008ex -0.744ex]{*}}
\def\cropddag{\raisebox{-.02ex}{\addvbuffer[0.02ex 0.02ex]{\ddag}}}
%% for TeX Gyre Schola %%%
%\usepackage{tgschola}
%\usepackage{textcomp}
%\def\cropast{\addvbuffer[0.02ex -0.64ex]{*}}
%\def\cropddag{\raisebox{.35ex}{\addvbuffer[-0.12ex -0.35ex]{\ddag}}}
%%%%%%%%%%%%%%%%%%%%%%%%%%
\newlength\tmplength
\def\stackedcropast#1{%
\stackengine{#1}{\cropast}{\cropast}{O}{c}{T}{F}{S}%
\tmplength=#1%
\tmplength=.5\tmplength%
\stackengine{\tmplength}{\usebox{\stackedbox}}{}{O}{c}{T}{F}{S}%
\stackengine{\tmplength}{\usebox{\stackedbox}}{}{U}{c}{F}{F}{S}%
}
\newcommand\textastdbl[1][0pt]{\scalerel*{$\stackedcropast{#1}$}{$\cropddag$}}
\begin{document}
\tiny cropast cropddag ddag\\
\Huge
\fboxsep=0pt\fboxrule=.02pt
\fbox{\cropast}~~\fbox{\cropddag}~~\fbox{\ddag}
\ddag\textastdbl\textastdbl[3pt]\textastdbl[6pt]\ddag x
\end{document}
The initial image below is running the code as is:
However, if the commented lines are uncommented, to activate the Tex Gyre Schola font, a slightly more complicated recropping gives the revised result for the new font, even when the original \ddag had a large buffer space below it. The fact that the central part of the Gyre \ddag is not symmetric with respect to the outer portion required the crop to place the \ddag centers at 25% and 75% of the crop-box vertical position.
Best Answer
For this problem the solution is quite simple:
so that the combination will be treated as a relation, since
=is a relation and TeX never puts space between two relation symbols. Sowill be rendered as
You might want to define a shorthand
and input the formula above as