Law of total expectation derivation

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In the proof of the Law of Total Expectation, the following identity confuses me

$$P(X=x|Y)P(Y=y)=P(X=x,Y=y)$$

I this the conditional probability formula? Is $P(X=x,Y=y)=P(X=x \cap Y=y)$?

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Yes and yes, although for clarity $|Y$ should read $|Y=y$.