Markdown 箭头与符号

显示	命令
\(\uparrow\)	\uparrow
\(\Uparrow\)	\Uparrow
\(\downarrow\)	\downarrow
\(\Downarrow\)	\Downarrow
\(\leftarrow\)	\leftarrow
\(\Leftarrow\)	\Leftarrow
\(\rightarrow\)	\rightarrow
\(\Rightarrow\)	\Rightarrow
\(\updownarrow\)	\updownarrow
\(\Updownarrow\)	\Updownarrow
\(\leftrightarrow\)	\leftrightarrow
\(\Leftrightarrow\)	\Leftrightarrow
\(\longleftarrow\)	\longleftarrow
\(\Longleftarrow\)	\Longleftarrow
\(\longrightarrow\)	\longrightarrow
\(\Longrightarrow\)	\Longrightarrow
\(\longleftrightarrow\)	\longleftrightarrow
\(\Longleftrightarrow\)	\Longleftrightarrow
\(\twoheadrightarrow\)	\twoheadrightarrow
\(\rightarrowtail\)	\rightarrowtail
\(\looparrowright\)	\looparrowright
\(\curvearrowright\)	\curvearrowright
\(\circlearrowright\)	\circlearrowright
\(\Rsh\)	\Rsh
\(\multimap\)	\multimap
\(\leftrightsquigarrow\)	\leftrightsquigarrow
\(\rightsquigarrow\)	\rightsquigarrow
\(\leadsto\)	\leadsto
\(\nearrow\)	\nearrow
\(\searrow\)	\searrow
\(\swarrow\)	\swarrow
\(\nwarrow\)	\nwarrow
\(\nleftarrow\)	\nleftarrow
\(\nrightarrow\)	\nrightarrow
\(\nLeftarrow\)	\nLeftarrow
\(\nRightarrow\)	\nRightarrow
\(\nleftrightarrow\)	\nleftrightarrow
\(\nLeftrightarrow\)	\nLeftrightarrow
\(\dashrightarrow\)	\dashrightarrow
\(\dashleftarrow\)	\dashleftarrow
\(\leftleftarrows\)	\leftleftarrows
\(\leftrightarrows\)	\leftrightarrows
\(\Lleftarrow\)	\Lleftarrow
\(\twoheadleftarrow\)	\twoheadleftarrow
\(\leftarrowtail\)	\leftarrowtail
\(\looparrowleft\)	\looparrowleft
\(\curvearrowleft\)	\curvearrowleft
\(\circlearrowleft\)	\circlearrowleft
\(\Lsh\)	\Lsh
\(\mapsto\)	\mapsto
\(\hookleftarrow\)	\hookleftarrow
\(\hookrightarrow\)	\hookrightarrow
\(\upharpoonright\)	\upharpoonright
\(\upharpoonleft\)	\upharpoonleft
\(\downharpoonright\)	\downharpoonright
\(\downharpoonleft\)	\downharpoonleft
\(\leftharpoonup\)	\leftharpoonup
\(\rightharpoonup\)	\rightharpoonup
\(\leftharpoondown\)	\leftharpoondown
\(\rightharpoondown\)	\rightharpoondown
\(\upuparrows\)	\upuparrows
\(\downdownarrows\)	\downdownarrows
\(\rightrightarrows\)	\rightrightarrows
\(\rightleftarrows\)	\rightleftarrows
\(\rightrightarrows\)	\rightrightarrows
\(\rightleftarrows\)	\rightleftarrows
\(\rightleftharpoons\)	\rightleftharpoons
\(\leftrightharpoons\)	\leftrightharpoons

希腊字母

小写	符号	大写	符号	小写	符号	大写	符号
α	\alpha	A	\Alpha	β	\beta	B	\Beta
γ	\gamma	Γ	\Gamma	δ	\delta	Δ	\Delta
ϵ	\epsilon	E	\Epsilon	ζ	\zeta	Z	\Zeta
η	\eta	H	\Eta	θ	\theta	Θ	\Theta
ι	\iota	I	\Iota	κ	\kappa	K	\Kappa
λ	\lambda	Λ	\Lambda	μ	\mu	M	\Mu
ν	\nu	N	\Nu	ξ	\xi	Ξ	\Xi
π	\pi	Π	\Pi	ρ	\rho	P	\Rho
σ	\sigma	Σ	\Sigma	τ	\tau	T	\Tau
υ	\upsilon	Υ	\Upsilon	ϕ	\phi	Φ	\Phi
χ	\chi	X	\Chi	ψ	\psi	Ψ	\psi
ω	omega	Ω	\Omega	ο	\omicron	O	\Omicron
若需要斜体希腊字母，加上前缀var。如\varDelta显示为\(\varDelta\)。

算术运算

显示	符号	显示	符号	显示	符号
×	\times	÷	\div	⋅	\cdot
<	<	>	>	≪	\ll
≫	\gg	⋘	\lll	±	\pm
≤	\le或\leq	≥	\ge或\geq	∓	\mp
≦	\leqq	≧	\geqq	≠	\neq
⩽	\leqslant	⩾	\geqslant	≈	\approx

更多：
https://www.cnblogs.com/ywsun/p/14271547.html