Equation 18.47 is written ```math \mathbf{\Sigma}_{* \mid X} = \mathbf{K}_{*,*} - \mathbf{K}_{X,*}^\top \mathbf{K}^{-1} \mathbf{K}_{X,*} ``` but should be ```math \mathbf{\Sigma}_{* \mid X} = \mathbf{K}_{*,*} - \mathbf{K}_{X,*}^\top \mathbf{K}_{X,X}^{-1} \mathbf{K}_{X,*} ```
