\supsetneqThe symbol \supsetneq denotes a strict superset relation, where one set is a superset of another set but not equal to it. In other words, it indicates that all elements of the second set are contained in the first set, and the first set has additional elements not present in the second set.
Set A is a strict superset of set B, meaning A contains all elements of B and more.
A \supsetneq BThe set {1, 2, 3} is a strict superset of the set {1, 2}.
\{1, 2, 3\} \supsetneq \{1, 2\}X is a strict superset of Y, indicating that X has all elements of Y plus additional elements.
X \supsetneq Y