A nawet jeszcze precyzyjniej
\(\displaystyle{ \psi\circ\left( \phi_1+\phi_2\right)\left( \alpha\right) =\psi\left( \left(\phi_1+\phi_2\right)(\alpha)\right)=\psi\left( \phi_1\left( \alpha\right)+\phi_2\left( \alpha\right) \right) =\psi\left( \phi_1\left( \alpha\right) \right)+\psi\left( \phi_2\left( \alpha\right) \right)=\psi\circ\phi_1\left( \alpha\right) +\psi\circ\phi_2\left( \alpha\right)}\)