\dotsb
The command \dotsb is used in LaTeX to produce an ellipsis (three dots) specifically for binary operations or relations. It ensures proper spacing in mathematical expressions where the ellipsis is part of a binary operation, such as addition, multiplication, or other similar operations.
Ellipsis in a series of additions
a_1 + a_2 + \dotsb + a_n
Ellipsis in a series of multiplications
x_1 \cdot x_2 \cdot \dotsb \cdot x_n
Ellipsis in a series of intersections
A_1 \cap A_2 \cap \dotsb \cap A_n