“One can also look at compound factors such as {{\mathcal B}_I \wedge {\mathcal B}_J}, the factor generated by the union of {{\mathcal B}_I} and {{\mathcal B}_J}.”

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“One can also look at compound factors such as {{\mathcal B}_I \vee {\mathcal B}_J}, the factor generated by the union of {{\mathcal B}_I} and {{\mathcal B}_J}.”

Where I have replaced the \wedge with the \vee?

*[Corrected, thanks – T.]*