Normal closure (group theory)

In group theory, the concept of normal closure is related to the idea of normal subgroups. Given a group \( G \) and a subset \( H \) of \( G \), the normal closure of \( H \) in \( G \), denoted by \( \langle H \rangle^G \) or sometimes \( \langle H \rangle^n \), is the smallest normal subgroup of \( G \) that contains the set \( H \).