Left Coset

Suppose that $G$ is a group and that $\varnothing \subset H\subseteq G$, then we define $$aH:=\{ah:h\in H\}$$

Left Coset

Suppose that $G$ is a group and that $\varnothing \subset H\subseteq G$, then we define $$Ha:=\{ha:h\in H\}$$