Similarly, important vector operations that we will deal with are addition and subtraction \begin{equation} \mathbf{x}= \mathbf{y}\pm\mathbf{z} \Longrightarrow x_{i} = y_{i}\pm z_{i}, \tag{6} \end{equation} scalar-vector multiplication \begin{equation} \mathbf{x}= \gamma\mathbf{y} \Longrightarrow x_{i} = \gamma y_{i}, \tag{7} \end{equation} vector-vector multiplication (called Hadamard multiplication)