To write "the chance that both X and Y are true" using standard Probability notation, we write $~$\mathbb{P}(X \wedge Y)$~$ or $~$\mathbb{P}(X, Y)$~$.
https://arbital.com/p/joint_probability
by Eliezer Yudkowsky Jan 26 2016 updated Jun 16 2016
The notation for writing the chance that both X and Y are true.
To write "the chance that both X and Y are true" using standard Probability notation, we write $~$\mathbb{P}(X \wedge Y)$~$ or $~$\mathbb{P}(X, Y)$~$.