Command for \longhookrightarrow

Question

The usual \rightarrow has its long version \longrightarrow, exactly as \mapsto has its long version \longmapsto. I was wondering if there exists a basic command for a long \hookrightarrowas well. The stupid try \longhookrightarrrow sadly doesn't work.

A separate question: On my machine the math-mode of the question is not rendered. Did I make some basic formatting mistakes? — Giovanni De Gaetano, Apr 10 '17 at 16:25
The table 166, Werner mentioned, refers to "Comprehensive LaTeX symbols" — samcarter_is_at_topanswers.xyz, Apr 10 '17 at 17:01

score 14 · Answer 1 · edited Apr 10 '17 at 16:45

14

I use \lhook\joinrel\xrightarrow to produce flexible arrows.

\documentclass{article}
\usepackage{amsmath}

\begin{document}
\[ A \lhook\joinrel\xrightarrow{f\circ g} B \]
\end{document}

edited Apr 10 '17 at 16:45

gernot

49,614

answered Apr 10 '17 at 16:40

Sigur

37,330

Thanks! It solves the problem, but I decided to accept the other answer for its simplicity. – Giovanni De Gaetano Apr 10 '17 at 16:50
1

Doesn't work for me for some reason: produces a short hookrightarrow... – mathreader Apr 24 '18 at 08:00
The length depends on what you insert above it. – Sigur Apr 24 '18 at 14:29

score 11 · Answer 2 · answered Apr 10 '17 at 17:19

No need for external packages:

\documentclass{article}

\newcommand{\hooklongrightarrow}{\lhook\joinrel\longrightarrow}
\newcommand{\hooklongleftarrow}{\longleftarrow\joinrel\rhook}

\begin{document}

$A\hooklongrightarrow B$

$A\hooklongleftarrow B$

\end{document}

The definition of \hookrightarrow is \lhook\joinrel\rightarrow, so it's very easy to complement it.

A comment. Beginners tend to overuse long arrows; stick with the short version: it's as clear and takes less space.

score 4 · Accepted Answer · answered Apr 10 '17 at 16:34

\documentclass{article}
\usepackage[new]{old-arrows}
\begin{document}
$x\hookrightarrow y$
$x\longhookrightarrow y$

$x\varhookrightarrow y$
$x\varlonghookrightarrow y$
\end{document}

How to find these glyphs: Open The Comprehensive LaTeX Symbol List and search for hook ...

score 3 · Answer 4 · answered Apr 10 '17 at 16:47

Here's a solution:

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}

\usepackage{amsmath}

\newcommand\hooklongrightarrow{\mathrel{\lhook\mkern -3.5mu\relbar\mkern -4.5mu → }}
\begin{document}
\setlength\arraycolsep{0pt}
\[ \begin{array}{@{\vrule width 0.1pt}l@{\vrule width 0.1pt}}
  \hooklongrightarrow\\
   ―――→
  \end{array}\]%

\end{document}

Command for \longhookrightarrow

4 Answers4