# Overlapping Arrows

I've been looking for arrow symbols that form a right angle, and 45' angles pointing to the upper-left and left of the symbol (combination of \leftarrow and \nwarrow, essentially). Generally, all combinations of the three arrows \leftarrow, \uparrow and \nwarrow.

I tried \mathrlap...

$\mathrlap{\leftarrow}\uparrow$


but the results were less than satisfactory --the origin of the arrows should be the same point.

-
Please, show us an image of the arrows. –  Sigur Jul 14 '14 at 13:01
Since they were just symbol composition, I didn't think that was necessary. Detextify didn't return a result. –  nlucaroni Jul 14 '14 at 13:11

The following example uses \uparrow as base unit, because the arrow reaches from the bottom to the top of the bounding box without interfering side bearings.

Macro \@leftuparrow takes three arguments with values 0 and 1 each to denote the left, northwest, and up arrow component of the total symbol.

As the examples show, a font for the up arrow should be used, where the tip is not too broad.

\documentclass{article}
\usepackage{amsmath}
%\usepackage{MnSymbol}
%\usepackage{mathabx}
\usepackage{graphicx}

\makeatletter
\newcommand*{\leftuparrow}{%
\@leftuparrow101%
}
\newcommand*{\loweredleftarrow}{\@leftuparrow100}
\newcommand*{\leftnwarrow}{\@leftuparrow110}
\newcommand*{\leftnwuparrow}{\@leftuparrow111}
\newcommand*{\nwuparrow}{\@leftuparrow011}
\newcommand*{\@leftuparrow}[3]{%
\mathrel{%
\mathpalette{\@@leftuparrow{#1}{#2}{#3}}{}%
}%
}
\newcommand*{\@@leftuparrow}[5]{%
% #1: left
% #2: nw
% #3: up
% #4: math style
% #5: unused
\sbox0{$#4\uparrow\m@th$}% base unit
%
% Correction of depth to compensate line width
\sbox6{$#4\mkern.25mu\m@th$}%
\dimen@=\dp0 %
\dp0=\dimen@
%
\sbox2{%
\rotatebox[origin=b]{45}{\hbox to\z@{\hss\copy0\hss}}%
}%
\sbox4{%
\rotatebox[origin=b]{90}{\copy0}%
}%
\dimen@=\z@
\dimen6=\z@
\ifnum#1#2>\z@
\kern4\wd6 % left side bearing
\fi
\ifnum#1=1 % leftarrow
\copy4 %
\dimen@=\wd4 %
\dimen6=\wd6 %
\fi
\ifnum#2=1 % nwarrow
\ifdim\dimen@>\z@
\llap{\copy2}%
\else
\copy2 %
\dimen@=\wd2 %
\dimen6=.7071\wd6 %
\fi
\fi
\ifnum#3=1 % uparrow
\ifdim\dimen@>\z@
\kern-.5\wd0 %
\fi
{\uparrow}%
\else
\kern4\wd6 % right side bearing
\fi
\kern\dimen6 %
}
\makeatother

\begin{document}
\newcommand*{\test}{%
\loweredleftarrow \leftnwarrow \leftnwuparrow
\leftuparrow \nwuparrow \uparrow
}
\setlength{\fboxsep}{0pt}%
\setlength{\fboxrule}{.1pt}%
\begin{gather*}
\fbox{$\leftarrow$}
\fbox{$\uparrow$}
\fbox{$\nwarrow$}
\\
\fbox{$\loweredleftarrow$}
\fbox{$\leftnwarrow$}
\fbox{$\leftnwuparrow$}
\fbox{$\leftuparrow$}
\fbox{$\nwuparrow$}
\\
\test\\
\scriptstyle\test\\
\scriptscriptstyle\test
\end{gather*}
\end{document}


Result for Computer Modern fonts:

Result for MnSymbol:

Result for mathabx:

-
\documentclass{article}
\usepackage{mathtools}
\begin{document}

$\raisebox{-1ex}{\leftarrow}\mathllap{\nwarrow}\mkern-10mu\uparrow$

\end{document}


-
So it's just about playing with the kerning to get them aligned. I guess that's what I should expect for combining symbols, thanks! –  nlucaroni Jul 14 '14 at 13:12
% arara: pdflatex

\documentclass{article}
\usepackage{tikz-cd}
\newcommand{\myArrow}[1]{\arrow[start anchor=center, end anchor=center]{#1}}
\newcommand{\nothing}{\phantom{\bullet}}

\begin{document}
\begin{tikzcd}[row sep=.5cm, column sep= .5cm]
\nothing&\nothing \\
\nothing&\nothing\myArrow{l}\myArrow{u}
\end{tikzcd}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{tikzcd}[row sep=.5cm, column sep= .5cm]
\nothing&\nothing \\
\nothing&\nothing\myArrow{ul}\myArrow{l}
\end{tikzcd}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{tikzcd}[row sep=.5cm, column sep= .5cm]
\nothing&\nothing \\
\nothing&\nothing\myArrow{ul}\myArrow{u}\myArrow{l}
\end{tikzcd}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{tikzcd}[row sep=.5cm, column sep= .5cm]
\nothing&\nothing \\
\nothing&\nothing\myArrow{ul}\myArrow{u}
\end{tikzcd}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{tikzcd}[row sep=.5cm, column sep= .5cm]
\nothing&\nothing \\
\nothing&\nothing\myArrow{l}
\end{tikzcd}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{tikzcd}[row sep=.5cm, column sep= .5cm]
\nothing&\nothing \\
\nothing&\nothing\myArrow{u}
\end{tikzcd}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{tikzcd}[row sep=.5cm, column sep= .5cm]
\nothing&\nothing \\
\nothing&\nothing\myArrow{ul}
\end{tikzcd}
\end{document}


-
If tikz is available it is easier to do \draw[<->] (-.5cm,0)--(0,0)--(0,.5cm); –  Sigur Jul 14 '14 at 13:45