自己常用的快捷键设置，冒号左面打出来+空格直接变右面的部分，#cursor表示光标位置，#tab表示一次tab键后光标位置，光标位置以此类推
下面这四个环境显示不全，就放在代码块里的，记得删去代码块前后的```
- ali:\begin{aligned} #cursor\end{aligned};
- cases:\left\{\begin{aligned}&#cursor\end{aligned}\right.;
- pma:\begin{pmatrix}#cursor\end{pmatrix};
- bma:\begin{bmatrix}#cursor\end{bmatrix};
- vma:\begin{vmatrix}#cursor\end{vmatrix};
unb:\underbrace{#cursor}_{#tab}#tab;
ovb:\overbrace{#cursor}^{#tab}#tab;
n}ti:n\times #cursor}#tab;
m}ti:m\times #cursor}#tab;
**:^{*};
y**:y^{*};
x**:x^{*};
A**:A^{*};
CC:C_{#cursor}^{#tab}#tab;
AA:A_{#cursor}^{#tab}#tab;
sq:\sqrt{#cursor}#tab;
sqn:\sqrt[#cursor]{#tab}#tab;
tag:\tag{#cursor}#tab;
tag1:\tag{1};
tag2:\tag{2};
tag3:\tag{3};
te:\text{#cursor}#tab;
ovs:\overset{#cursor}{#tab}#tab;
uns:\underset{#cursor}{#tab}#tab;
fr:\frac{#cursor}{#tab}#tab;
frp:\frac{\partial #cursor}{\partial #tab}#tab;
frpp:\frac{\partial^{2} #cursor}{\partial #tab^{2}}#tab;
frphp:\frac{\partial^{2} #cursor}{\partial #tab \partial #tab}#tab;
frppp:\frac{\partial^{#cursor} #tab}{\partial #tab^{#tab}}#tab;
lim:\lim\limits_{#cursor}#tab;
limninf:\lim\limits_{n\to\infty};
limxinf:\lim\limits_{x\to\infty};
limx+inf:\lim\limits_{x\to+\infty};
limx-inf:\lim\limits_{x\to-\infty};
limt+inf:\lim\limits_{t\to+\infty};
limt-inf:\lim\limits_{t\to-\infty};
limx0:\lim\limits_{x\to0};
limxy0:\lim\limits_{\substack{x\to0\\y\to0}};
subxy:\substack{x=#cursor\\ y=#tab}#tab;
subs:\substack{#cursor}#tab;
limkwy0:\lim\limits_{(x,y)\to(0,0)};
limxy:\lim\limits_{\substack{x\to#cursor\\y\to #tab}}#tab;
limkxy:\lim\limits_{(x,y)\to(#cursor,#tab)}#tab;
limk:\lim\limits_{(#cursor,#tab)\to(#tab,#tab)}#tab;
lims:\lim\limits_{\substack{#cursor\to #tab\\ #tab\to #tab}}#tab;
limx0+:\lim\limits_{x\to0^{+}};
limx0-:\lim\limits_{x\to0^{-}};
int:\int_{#cursor}^{#tab}#tab;
intt:\int\limits_{#cursor}#tab;
iint:\iint_{#cursor}^{#tab}#tab;
iintt:\iint\limits_{#cursor}#tab;
sum:\sum\limits_{#cursor}^{#tab}#tab;
sumn1inf:\sum\limits_{n=1}^{\infty};
sumn0inf:\sum\limits_{n=0}^{\infty};
sumninf:\sum\limits_{n=#cursor}^{\infty}#tab;
sumi1N:\sum\limits_{i=1}^{N};
sumj1N:\sum\limits_{j=1}^{N};
sumj1p:\sum\limits_{j=1}^{p};
sumn1N:\sum\limits_{n=1}^{N};
sumi1n:\sum\limits_{i=1}^{n};
sumk1K:\sum\limits_{k=1}^{K};
prodi1n:\prod\limits_{i=1}^{n};
prodi1N:\prod\limits_{i=1}^{N};
prodj1p:\prod\limits_{j=1}^{p};
prodn1N:\prod\limits_{n=1}^{N};
prod:\prod\limits_{#cursor}^{#tab}#tab;
ll:\Big|_{#cursor}^{#tab}#tab;
12,:1,2,\cdots,n;
12N,:1,2,\cdots,N;
12n2,:1^{2},2^{2},\cdots,n^{2};
x123,:x_{1},x_{2},x_{3};
x12N,:x_{1},x_{2},\cdots,x_{N};
X12n,:X_{1},X_{2},\cdots,X_{n};
x12,:x_{1},x_{2};
y123,:y_{1},y_{2},y_{3};
z123,:z_{1},z_{2},z_{3};
x00:x_{0};
x11:x_{1};
x112:x_{1}^{2};
x22:x_{2};
x222:x_{2}^{2};
x33:x_{3};
x332:x_{3}^{2};
y00:y_{0};
y11:y_{1};
y112:y_{1}^{2};
y22:y_{2};
y222:y_{2}^{2};
y33:y_{3};
y332:y_{3}^{2};
z11:z_{1};
z112:z_{1}^{2};
z22:z_{2};
z222:z_{2}^{2};
z33:z_{3};
z332:z_{3}^{2};
xnn:x_{n};
xnn2:x_{n}^{2};
x12n,:x_{1},x_{2},\cdots,x_{n};
A11:A_{1};
A22:A_{2};
A33:A_{3};
a11:a_{1};
a22:a_{2};
a33:a_{3};
Ann:A_{n};
Aii:A_{i};
Ajj:A_{j};
A12n,:A_{1},A_{2},\cdots,A_{n};
B11:B_{1};
B22:B_{2};
B33:B_{3};
b11:b_{1};
b22:b_{2};
b33:b_{3};
Bnn:B_{n};
Bii:B_{i};
Bjj:B_{j};
B12n,:B_{1},B_{2},\cdots ,B_{n};
122+:1^{2}+2^{2}+\cdots+n^{2};
12n,:1,2,\cdots,n;
ria:\rightarrow ;
Ria:\Rightarrow ;
Lra:\Leftrightarrow ;
to:\to ;
inf:\infty;
cds:\cdots ;
cd:\cdot ;
vds:\vdots ;
dds:\ddots ;
ti:\times ;
al:\alpha;
al11:\alpha_{1};
\alpha11:\alpha_{1};
al22:\alpha_{2};
\alpha22:\alpha_{2};
al33:\alpha_{3};
\alpha33:\alpha_{3};
al123,:\alpha_{1},\alpha_{2},\alpha_{3};
al12n,:\alpha^{1},\alpha^{2},\cdots,\alpha^{n};
alTT:\alpha^{T};
be:\beta;
be11:\beta_{1};
be22:\beta_{2};
be33:\beta_{3};
beTT:\beta^{T};
miT:^{T};
ga:\gamma;
ga11:\gamma_{1};
ga22:\gamma_{2};
ga33:\gamma_{3};
ga123,:\gamma_{1},\gamma_{2},\gamma_{3};
ga12n,:\gamma_{1},\gamma_{2},\cdots,\gamma_{n};
Ga:\Gamma ;
de:\delta;
De:\Delta ;
De1:\Delta_{1};
De2:\Delta_{2};
De3:\Delta_{3};
De4:\Delta_{4};
ep:\epsilon ;
ze:\zeta;
et:\eta;
th:\theta;
th12k,:\theta_{1},\theta_{2},\cdots,\theta_{k};
Th:\Theta;
io:\iota ;
ka:\kappa ;
la:\lambda;
la1:\lambda_{1};
la2:\lambda_{2};
la3:\lambda_{3};
lan:\lambda_{n};
la123,:\lambda_{1},\lambda_{2},\lambda_{3};
la12n,:\lambda_{1},\lambda_{2},\cdots,\lambda_{n};
La:\Lambda;
mu:\mu;
nu:\nu ;
xi:\xi;
Xi:\Xi ;
pi:\pi;
Pi:\Pi ;
rh:\rho;
si:\sigma;
Si:\Sigma;
ta:\tau ;
up:\upsilon ;
Up:\Upsilon ;
ph:\phi;
Ph:\Phi ;
ch:\chi;
na:\nabla;
ps:\psi;
Ps:\Psi ;
om:\omega;
Om:\Omega;
pa:\partial ;
qu:\quad ;
sin:\sin ;
cos:\cos ;
tan:\tan ;
cot:\cot ;
sec:\sec ;
csc:\csc ;
arcsin:\arcsin ;
arccos:\arccos ;
arctan:\arctan ;
ne:\ne ;
sim:\sim ;
sime:\simeq ;
sub:\subset ;
sul:\subset ;
sup:\supset ;
sur:\supset ;
\subset pp:\supset ;
\supset bb:\subset ;
pm:\pm ;
in:\in ;
ca:\cap ;
cap:\cap ;
\cup aa:\cap ;
\cap aa:\bigcap\limits_{#cursor}^{#tab}#tab;
caa:\bigcap\limits_{#cursor}^{#tab}#tab;
caai1n:\bigcap\limits_{i=1}^{n};
cu:\cup ;
cup:\cup ;
\cap uu:\cup ;
\cup uu:\bigcup\limits_{#cursor}^{#tab}#tab;
cuu:\bigcup\limits_{#cursor}^{#tab}#tab;
cuui1n:\bigcup\limits_{i=1}^{n};
not:\varnothing;
and:& ;
leq:\leq ;
geq:\geq ;
ln:\ln ;
max:\max ;
maxl:\max\limits_{#cursor}#tab;
min:\min ;
eqv:\equiv ;
ee:e^{x};
e-e:e^{-x};
TT:^{T};
ys:原式&=;
jkh:\left<#cursor\right>#tab;
dkh:\left\{#cursor\right\}#tab;
|kh:\left|#cursor\right|#tab;
lkh:\left|#cursor\right|#tab;
bar:\bar{#cursor}#tab;
barr:\overline{#cursor}#tab;
ovl:\overline{#cursor}#tab;
\bar{}l:\overline{#cursor}#tab;
hat:\hat{#cursor}#tab;
til:\tilde{#cursor}#tab;
fxx:f_{x};
f11:f_{1};
zxx:z_{x};
fxxx:f_{xx};
f111:f_{11};
fyy:f_{y};
f22:f_{2};
zyy:z_{y};
fyyy:f_{yy};
f222:f_{22};
fxxy:f_{xy};
f112:f_{12};
fyyx:f_{yx};
f221:f_{21};
，:,;
、、:\\;
cov:\text{cov};
exp:\text{exp};
log:\log;
MLE:\text{MLE};
MAP:\text{MAP};
argmax:\text{argmax };
argmaxd:\mathop{\text{argmax}\space}\limits_{#cursor}#tab;
argmin:\text{argmin };
argmind:\mathop{\text{argmin}\space}\limits_{#cursor}#tab;
mbb:\mathbb{#cursor}#tab;
bbR:\mathbb{R};
var:\text{Var};
Var:\text{Var};
Cov:\text{Cov};
cov:\text{Cov};
tr:\text{tr};
II:\text{I};
IIN:\mathbb{I}_{N};
bbI:\mathbb{I};
bbIN:\mathbb{I}_{N};
HH:\mathbb{H};
OO:\mathbb{O};
bbO:\mathbb{O};
mind:\mathop{\text{min }}\limits_{#cursor}#tab;
maxd:\mathop{\text{max }}\limits_{#cursor}#tab;
llkh:\left|\left|#cursor\right|\right|#tab;
det:\text{det};
box:\boldsymbol{x};
bof:\boldsymbol{f};
xx:\boldsymbol{x};
ff:\boldsymbol{f};
vec:\text{vec};