I have come across an inequation in an optimization paper.
$$\left\lVert x\right\rVert _{2} \leq G$$ $$\left\lVert x\right\rVert _{\infty} \leq G_{\infty}$$
I know that the euclidean norm of a vector is bound by some real number $G$, but what does it mean in the second inequation? what is the $G_{\infty}$ mean?