How to type this diagram on math.stackexchange? [duplicate]

Is there a way to type this diagram on math.stackexchange?

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For example, I know there is a way to type CD commutative diagram like this: $$\begin{array}{ccc} SL(2,R)\times S^1 & \longrightarrow & S^1\\ \downarrow &~& \downarrow\\ PSL(2,R)\times RP^1 & \longrightarrow &RP^1 \end{array}$$