[Summary of input methods for Markdown arrows]

1. Normal arrow

arrow shape	MarkDown
$\uparrow$	$\uparrow$
$\Uparrow$	$\Uparrow$
$\downarrow$	$\downarrow$
$\Downarrow$	$\Downarrow$
$\leftarrow$	$\leftarrow$
$\Leftarrow$	$\Leftarrow$
$\to$	$\rightarrow$
$\Rightarrow$	$\Rightarrow$
$\updownarrow$	$\updownarrow$
$\Updownarrow$	$\Updownarrow$
$\leftrightarrow$	$\leftrightarrow$
$\iff$	$\Leftrightarrow$

2. Long Arrow

arrow shape	MarkDown
$⟵$	$\longleftarrow$
$⟸$	$\Longleftarrow$
$⟶$	$\longrightarrow$
$⟹$	$\Longrightarrow$
$⟷$	$\longleftrightarrow$
$⟺$	$\Longleftrightarrow$

3. Other arrows

arrow shape	MarkDown
$\twoheadrightarrow$	$\twoheadrightarrow$
$\rightarrowtail$	$\rightarrowtail$
$\looparrowright$	$\looparrowright$
$\curvearrowright$	$\curvearrowright$
$\circlearrowright$	$\circlearrowright$
$\Rsh$	$\Rsh$
$⊸$	$\multimap$
$\leftrightsquigarrow$	$\leftrightsquigarrow$
$⇝$	$\rightsquigarrow$
$⇝$	$\leadsto$
$\nearrow$	$\nearrow$
$\searrow$	$\searrow$
$\swarrow$	$\swarrow$
$\nwarrow$	$\nwarrow$
$\nleftarrow$	$\nleftarrow$
$\nLeftarrow$	$\nLeftarrow$
$\nrightarrow$	$\nrightarrow$
$\nRightarrow$	$\nRightarrow$
$\nleftrightarrow$	$\nleftrightarrow$
$\nLeftrightarrow$	$\nLeftrightarrow$
$⇢$	$\dashrightarrow$
$⇠$	$\dashleftarrow$
$\leftleftarrows$	$\leftleftarrows$
$\leftrightarrows$	$\leftrightarrows$
$\Lleftarrow$	$\Lleftarrow$
$\twoheadleftarrow$	$\twoheadleftarrow$
$\leftarrowtail$	$\leftarrowtail$
$\looparrowleft$	$\looparrowleft$
$\curvearrowleft$	$\curvearrowleft$

---

箭头形状	MarkDown
$\circlearrowleft$	$\circlearrowleft$
$\Lsh$	$\Lsh$
$\mapsto$	$\mapsto$
$\hookleftarrow$	$\hookleftarrow$
$\hookrightarrow$	$\hookrightarrow$
$\upharpoonright$	$\upharpoonright$
$\upharpoonleft$	$\upharpoonleft$
$\downharpoonright$	$\downharpoonright$
$\downharpoonleft$	$\downharpoonleft$
$\leftharpoonup$	$\leftharpoonup$
$\rightharpoonup$	$\rightharpoonup$
$\rightharpoondown$	$\rightharpoondown$
$\leftharpoondown$	$\leftharpoondown$
$\upuparrows$	$\upuparrows$
$\downdownarrows$	$\downdownarrows$
$\rightrightarrows$	$\rightrightarrows$
$\rightleftarrows$	$\rightleftarrows$
$\leftleftarrows$	$\leftleftarrows$
$\leftrightarrows$	$\leftrightarrows$
$\rightleftharpoons$	$\rightleftharpoons$
$\leftrightharpoons$	$\leftrightharpoons$