/sci/ - Science & Math

So does [math]m_{B_1\; \cap B_2} = \inf_{x\in\mathcal{B} }f(x)[/math], where [math]\mathcal{B}[/math] is any base that contains [math]B_1 \cap B_2[/math], or is it a typo and supposed to be [math]m_{B_1\; \cap B_2} = \inf_{x\in B_1 \cap B_2 }f(x)[/math]?