Verify the following property: $\forall ( A , B ) \in \left( \mathcal { M } _ { n } ( \mathbb { C } ) \right) ^ { 2 } \quad \| A B \| _ { 0 } \leqslant n \| A \| _ { 0 } \cdot \| B \| _ { 0 }$
Verify the following property: $\forall ( A , B ) \in \left( \mathcal { M } _ { n } ( \mathbb { C } ) \right) ^ { 2 } \quad \| A B \| _ { 0 } \leqslant n \| A \| _ { 0 } \cdot \| B \| _ { 0 }$