\amalgThe \amalg symbol is used to denote a coproduct in category theory, which is a concept from abstract algebra. It represents a construction that generalizes the disjoint union of sets and the direct sum of modules.
Coproduct of objects A and B in a category
A \amalg BCoproduct of multiple objects X, Y, and Z
X \amalg Y \amalg ZCoproduct of a family of objects indexed by I
\amalg_{i \in I} A_i