\hookrightarrowThe symbol \hookrightarrow is used to denote an injective (one-to-one) function or mapping in mathematics. It is often used in the context of category theory, algebra, and topology to indicate that one set or space is being embedded into another.
Indicates that set A is injectively mapped into set B.
A \hookrightarrow BDenotes that vector space V is embedded into vector space W.
V \hookrightarrow WShows that topological space X is embedded into topological space Y.
X \hookrightarrow Y