delimitersmath-modesymbols
This is a subquestion related to Evaluation Symbol.
Is there something of the form \left<?> instead of \left. telling LaTeX to enclose the expression here and not to insert any delimiter at all, no matter wether visible or invisible?
As an example I want:
\left<no-delimiter><stuff>\right|_<index>
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.
I would say that footnote in equations is not really a good practice, and you should find another way to do that...
However, perhaps you could change the mark to get a less ambiguous symbol (dagger etc.)
\renewcommand\thefootnote{\fnsymbol{footnote}}
Edit:
As pointed out in a comment, using symbols can also be confusing (since \dagger can typically be a Hermitian conjugate in quantum mechanics...); another possibility would be to use circled numbers (as proposed in an answer of this question) with the pifont package
% circled number: ①②③④⑤⑥⑦⑧⑨
\usepackage{pifont}
\renewcommand\thefootnote{\ding{\numexpr171+\value{footnote}}}
Best Answer
When
\left.is used, TeX inserts no delimiter, but adds a space of width\nulldelimiterspace. It's not advisable to set this parameter to zero, in my opinion. But withusing
will in any case remove the added space.
As explained in my answer to the referenced question, using a macro would be much better for ensuring consistency. If your aim is to get code that works also with MathJax out of the box, you're on the wrong road: the capabilities of MathJax are limited and so you are forcing yourself into using bad LaTeX.