latex公式编辑

$$$J_\alpha(x) = \sum\limits_{m=0}^\infty \frac{(-1)^m}{m! \, \Gamma(m + \alpha + 1)}{\left({\frac{x}{2}}\right)}^{2 m + \alpha}$$$##上下标- - -$$$x^{2},x^{(n)}_{2},^{-16}O_{32}^{2-},x^{y^{z^{a}}},x^{y_{z}},\partial f_{\tiny hfd};y_N, y_{_N},y_{_{\scriptstyle N}}$$$##分数- - -$$$\frac{a}{b},a/b,\frac{x+y}{y+z},\displaystyle\frac{x+y}{x+z},x_0 + \frac{1}{x_1+\frac{1}{x_2+\frac{1}{x_4}}},\frac{1}{2},\frac{\;1\;}{\;2\;}$$$$$\frac{x+y}{y+z}$$##根号- - -$$\sqrt 2,\sqrt{x},\sqrt[n]{x},\sqrt{a}+\sqrt{b}+\sqrt{c},\sqrt{\mathstrut a}+\sqrt{\mathstrut b},\begin{eqnarray}\sqrt{1+\sqrt[p]{1+\sqrt[q]{1+a}}}\\\sqrt{1+\sqrt[^p\!]{1+\sqrt[^q\!]{1+a}}}\end{eqnarray},^n\!a,\surd{\frac{x+y+z}{abc}}$$##求和$$$\sum_{k=1}^n,\int_a^b,\sum_{k=1}^\infty \frac{x^n}{n!},\$$$$$\sum_{k=1}^\infty \frac{x^n}{n!},\sum_{\infty}^{k=1}\frac{x^n}{n!},\int_0^\infty e^x,\sum_{k=1}^\infty = \int_0^\infty e^x,\sum\limits_{k=1}^{\infty},\sum\nolimits_{k=1}^{\infty},$$##下划线$$$\overline{a-b},\underline{a+b},\overbrace{a+b}^{上括弧},\underbrace{a-b}_{下括弧},\dots$$$$$$\hat{a},\check{a},\breve{a},\tilde{a},\bar{a},\vec{a},\acute{a},\grave{a},\mathring{a},\dot{a},\ddot{a},\widehat{a,b,c},\widetilde{xyz}$$$##堆积符号$$$\begin{eqnarray*}\vec{x}\stackrel{\mathrm{def}}{=}{x_1, \dots, x_n}\\{n+1 \choose k}={n \choose k} + {n \choose k-1}\\\sum_{k_0,k_1,\ldots>0 \atop k_0+k_1+\cdots=n}A_{k_0}A_{k_1}\cdots\end{eqnarray*},\;\;\;\;\vec{1},\stackrel{\mathrm{def}}{=}{x_1, \dots, x_n},{n+1 \choose k} = {n \choose k}+{n \choose k-1},\sum\limits_{k_0,  k_1,\ldots>0 \atop k_0 +k_1 + \cdots = n}A_{k_0}A_{k_1}$$$$${n \choose k}, \ldots$$##定界符$$$()\big(\big)\Big(\Big)\bigg(\bigg)\Bigg(\Bigg)$$$