I want to create from suitable symbols ‐ and not using TikZ or other drawing method — large sum (\bigsum
) and large times (\mybigtimes
) math symbols, for cartesian sum and cartesian product, respectively, that:
- are the same vertical size as
\bigcup
and\bigcap
; - have strokes with the same thickness as the curves in
\bigcup
and\bigcap
; - in the case of
\mybigtimes
, is scaled down horizontally only; - will scale properly for in-line math, display math, etc. (presumably, by using
\mathchoice
; and - will work with both pdfLaTeX and `XeLaTeX.
How can this be done?
Here is what I have so far. The output shown is produced only when the part after This does \emph{not} work
is commented out.
\documentclass[12pt,fleqn]{article}
\usepackage{amsmath}
\usepackage{iftex}
\ifTUTeX
\usepackage{fontspec}
\usepackage{unicode-math}
\defaultfontfeatures{ Scale=MatchLowercase, Ligatures=TeX }
\setmainfont{TeX Gyre Termes}[Scale=1.0]
\setmathfont{TeX Gyre Termes Math}
\mathchardef\timessymbol=\numexpr\times-"2000\relax % WHAT IS THE NAME-NUMBER?
\else
\RequirePackage[scaled=0.93]{newtxtext}
\RequirePackage{newtxmath}%
\mathchardef\timessymbol=\numexpr\times-"2000\relax % WHAT IS THE NAME-NUMBER?
\fi
\usepackage{graphicx}
\usepackage{scalerel}
\DeclareMathOperator*{\bigplus}{\scalerel*{+}{\sum}}
\DeclareMathOperator*{\Bigplus}{\scalerel*{+}{\textstyle\sum}}
% Attempt to shrink a big times horizontally:
\DeclareMathOperator*{\mybigtimes}{\scalebox{0.7}[1]{\timessymbol}}
\begin{document}
\ifTUTeX With Xe\LaTeX\else With pdf\LaTeX\fi
\bigskip
These work, but geometry is wrong:
\bigskip
$\bigtimes_{n=0}^{\infty} X_{i} = \bigcup_{k=0}^{\infty}U_{k}$
\quad to shrink \verb!\bigtimes! horizontally (but not vertically)
\bigskip
$\bigplus_{n=0}^{\infty} X_{i} = \bigcap_{k=0}^{\infty}U_{k}$ \quad \verb!\bigsum! too thick
%
\begin{gather*}
\bigtimes_{n=0}^{\infty} X_{i}= \bigcup_{k=0}^{\infty}U_{k}
\quad \text{to shrink bigtimes symbol horizontally (but not vertically)}
\\
\bigplus_{n=0}^{\infty} X_{i} = \bigcap_{k=0}^{\infty}U_{k}
\quad \text{bigplus symbol too thick}
\end{gather*}
This does \emph{not} work:
$\mybigtimes_{n=0}^{\infty} X_{i}$
\[
\mybigtimes_{n=0}^{\infty} X_{i}
\]
\end{document}
Related:
https://tex.stackexchange.com/a/394912/13492
Big cartesian product & cartesian sum symbols with Lucida Math fonts?
Continuation: See Make non-square bigtimes.
\cup
, and select the thickness based on\mathchoice
.