math-modespacing
This piece of code
\documentclass{article}
\usepackage{mathtools}
\begin{document}
\[\smashoperator[r]{\sum_{s=n-t+1}^{j-1}}s-(n-t)=\sum_{s=1}^{j-1-(n-t)}s=\frac{\bigl(j-1-(n-t)\bigr)\bigl(j-(n-t)\bigr)}{2}\]
\end{document}
produces
I’d like to have
commands like \smashoperator or \mathclap are of no use as the width of the upper limit is correctly pushing the equal signs apart. How can I give TeX a hint that I want to move the summand s close to the sigma and under the upper limit?
The only difference I could see was the spacing between the rows that caused some of the equations to lie on the cline.
Adding [.1cm] or whatever distance separation you want will achieve a bigger spacing.
\documentclass{article}
\usepackage{amsmath, array}
\begin{document}
\begin{align*}
\renewcommand\arraystretch{2}
\begin{array}{r@{\hskip\arraycolsep}c@{\hskip\arraycolsep}l*2r}
&&\dfrac{1}{z}+\dfrac{1}{3!}z&+\left[\dfrac{1}{(3!)^2}-\dfrac{1}{5!}\right]z^3+ \cdots\\[.1cm]
\cline{2-4}
z-\dfrac{1}{3!}z^3+\dfrac{1}{5!}z^4-\cdots&\Bigg)&1\\[.1cm]
&&1-\dfrac{1}{3!}z^2&+\dfrac{1}{5!}z^4-\cdots\\[.1cm]
\cline{2-4}
&&\hfill\dfrac{1}{3!}z^2&-\dfrac{1}{5!}z^4+\cdots\\[.1cm]
&&\hfill\dfrac{1}{3!}z^2&-\dfrac{1}{(3!)^2}z^4+\cdots\\[.1cm]
\cline{2-4}
&&&\left[\dfrac{1}{(3!)^2}-\dfrac{1}{5!}\right]z^4-\cdots\\[.1cm]
&&&\left[\dfrac{1}{(3!)^2}-\dfrac{1}{5!}\right]z^4-\cdots\\[.1cm]
\cline{2-4}
&&&\multicolumn{1}{c}{\vdots}\\
\end{array}
\end{align*}
\end{document}
Also, if you want to use a square root in stead of ) and \cline, you could do
\sqrt{1 + \phantom{\left(\frac{10^{2}}{10^{2}}\right)+50000000000000000000000000}}
Then you will have to adjust your spacing of division. You could then adjust +50000000... to cover as much width as you need. There may be even a smooth way to extend the radical without using phantom. I will look into and see if I can find something or maybe someone else will know.
Instead of using \phantom alone, I have adapted Werner's solution from
Large Square Root Symbols
\newcommand{\blank}[1]{\hfil\penalty1000\hfilneg\rule[-3pt]{#1}{1cm}}
\[ 3 = \sqrt{\phantom{\blank{5cm}}} \]
I modified his example to take care of height too. You can adjust this to whatever you want by changing 1cm and the width is argument of \blank. So this produces:
Furthermore, we can adapt How can I create a multiline split inside of a radical inside of an array environment? in order to use the radical in better manner.
By using aligned environment, we can achieve the image below (I only edited the first few lines as an example)
The code is:
\documentclass{article}
\usepackage{amsmath, array}
\begin{document}
\begin{align*}
\renewcommand\arraystretch{2}
\newcommand{\blank}[1]{\hfil\penalty1000\hfilneg\rule[-3pt]{#1}{.75cm}}
\begin{array}{r@{\hskip\arraycolsep}c@{\hskip\arraycolsep}l*2r}
&&\begin{aligned}
\quad\dfrac{1}{z}&+\dfrac{1}{3!}z
+\bigg[\dfrac{1}{(3!)^2}-\dfrac{1}{5!}\bigg]z^3 +\cdots
\end{aligned}\\[.1cm]
z-\dfrac{1}{3!}z^3+\dfrac{1}{5!}z^4-\cdots&&\sqrt{\begin{aligned}
1 & \phantom{\blank{4.5cm}}
\end{aligned}}\\[.1cm]
&&\begin{aligned}
\quad 1&-\dfrac{1}{3!}z^2 & \phantom{5\bigg[\dfrac{1}{3}} \quad
+\dfrac{1}{5!}z^4-\cdots
\end{aligned}\\[.1cm]
\cline{2-3}
&&\begin{aligned}
\quad\phantom{1\hspace{.15cm}-}\dfrac{1}{3!}z^2 &
\phantom{55l\bigg[\dfrac{1}{3!}}
\quad-\dfrac{1}{5!}z^4+\cdots
\end{aligned}\\[.05cm]
\end{array}
\end{align*}
\end{document}
TeX sets \thickmuskip between the relational operator and most other math atoms in styles \displaystyle and \textstyle, but no space in script styles \scriptstyle and \scriptscriptstyle.
A \thinspace is also inserted in script styles between an operator atom (\mathop) and an ordinary atom (\mathord). Thus
\sum_{n \mathop{=} 1}
gets you the desired spacing:
However:
\displaystyle and \textstyle.\mathop vertically centers the symbol, e.g.:
\sum_{n \mathop{.} 1}
The dot is moved to the math axis and becomes a "\cdot".
This is not a problem for the equals sign, because this is usually already centered around the math axis.
The spacing can be manually fixed by adding \, as suggested in Werner's comment:
\sum_{n \,=\, 1}
Advantage:
A small disadvantage remains:
\displaystyle and \textstyleThere is a trick to circumvent the latter: \nonscript suppresses the following space in the script styles.
\documentclass{article}
\newcommand*{\mrel}[1]{%
\mskip\thinmuskip
\nonscript\mskip-\thinmuskip
\mathrel{#1}%
\mskip\thinmuskip
\nonscript\mskip-\thinmuskip
}
\begin{document}
\[ \sum_{n \mrel= 1} \mrel= 1 \]
\end{document}
\thinmuskip is added in script styles, otherwise it is canceled by -\thinmuskip.
In LuaTeX the spacings between the math atoms can be configured very deeply.
Also the cramped styles are available as commands. Cramped styles are used, if something is above the expression (denominator, \sqrt, ...). Then superscripts are lowered a bit. Cramped style is used in the subscript of \sum.
The following example configures a thin space between math atoms in \scriptstyle and cramped \scriptstyle, where a thick space would be set in \textstyle or \displaystyle.
\documentclass{article}
\usepackage{ifluatex}
\makeatletter
\ifluatex
\def\@tempa#1#2#3{%
\csname luatexUmath#1#2spacing\endcsname\luatexcrampedscriptstyle=#3\relax
\csname luatexUmath#1#2spacing\endcsname\scriptstyle=#3\relax
}%
\@for\@tempb:={ord,op,close,inner}\do{%
\@tempa\@tempb{rel}\thinmuskip
}%
\@for\@tempb:={ord,op,open,inner}\do{%
\@tempa{rel}\@tempb\thinmuskip
}%
\fi
\makeatother
\begin{document}
\[ \sum_{n = 1}^{n = 1} \]
\end{document}
Remarks:
luatex for new LuaTeX commands
to avoid name clashes with existing macros.\@for loops avoid a long list of
assignments.
Best Answer