Indicates an implicit relationship. It means that if A is true, it can be inferred that B is true (when A is false, it is agreed that B is not true or false, and the implication is true).
Implication can be understood literally, that is, the occurrence of this event of A implies that this event of B also occurred.
From the point of view of set, it is equivalent that set A contains set B.
Equivalent to? A∨B