A binary operator representing the greatest lower bound or meet operation in lattice theory and set theory.
Examples
Meet operation in lattice theory
a \sqcap b \sqcap c \text{ represents the meet of } a, b, \text{ and } c
Greatest lower bound in a semilattice
x_1 \sqcap x_2 = \text{glb}\{x_1, x_2\}
Intersection of fuzzy sets
(A \sqcap B)(x) = \min\{A(x), B(x)\}