In the new updated version of the article “Funcoids and Reloids” I proved the following theorem:

**Theorem** Filter objects $latex \mathcal{A}$ and $latex \mathcal{B}$ are isomorphic iff exists a monovalued injective reloid $latex f$ such that $latex \mathrm{dom}f = \mathcal{A}$ and $latex \mathrm{im}f = \mathcal{B}$.