参考:https://www.jianshu.com/p/08cbe54a5f33
[ 1 2 3 4 ] \left[ \begin{matrix} 1 & 2 \\ 3 & 4 \end{matrix} \right] [1324]
$$
\left[
\begin{matrix}
1 & 2 \\
3 & 4
\end{matrix}
\right]
$$
name1 | name2 | name3 |
---|---|---|
a | b | c |
d | e | f |
| name1 | name2 | name3 |
| ---- | ---- | ---- |
| a | b | c |
| d | e | f |
参考:https://zhidao.baidu.com/question/500652228447668004.html
跟latex的语法差不多,只是要用一对$$
包起来。
$$
\begin{aligned}
G &= \{A_1 \rightarrow (A_2, A_3); A_3 \rightarrow A_4\} \cup \{(A_2, A_3) \rightarrow (A_5, A_6); A_5 \rightarrow A_2\} \\
&= \{A_1 \rightarrow (A_2, A_3); A_3 \rightarrow A_4; (A_2, A_3) \rightarrow (A_5, A_6); A_5 \rightarrow A_2\}
\end{aligned}
$$
G = { A 1 → ( A 2 , A 3 ) ; A 3 → A 4 } ∪ { ( A 2 , A 3 ) → ( A 5 , A 6 ) ; A 5 → A 2 } = { A 1 → ( A 2 , A 3 ) ; A 3 → A 4 ; ( A 2 , A 3 ) → ( A 5 , A 6 ) ; A 5 → A 2 } \begin{aligned} G &= \{A_1 \rightarrow (A_2, A_3); A_3 \rightarrow A_4\} \cup \{(A_2, A_3) \rightarrow (A_5, A_6); A_5 \rightarrow A_2\} \\ &= \{A_1 \rightarrow (A_2, A_3); A_3 \rightarrow A_4; (A_2, A_3) \rightarrow (A_5, A_6); A_5 \rightarrow A_2\} \end{aligned} G={ A1→(A2,A3);A3→A4}∪{ (A2,A3)→(A5,A6);A5→A2}={ A1→(A2,A3);A3→A4;(A2,A3)→(A5,A6);A5→A2}
参考:https://www.jianshu.com/p/763e5b531d8f
Z = X
WHILE Z变化 DO
对每个关系$R_i$,
$Z = Z\cup ((Z\cap R_i)^+ \cap R_i)$
在vscode中
但是在csdn中是这样:
Z = X
WHILE Z变化 DO
对每个关系 R i R_i Ri,
Z = Z ∪ ( ( Z ∩ R i ) + ∩ R i ) Z = Z\cup ((Z\cap R_i)^+ \cap R_i) Z=Z∪((Z∩Ri)+∩Ri)
这是因为csdn为了用户体验,把原本的回车也显示出来了。
a
b
a
b