EN
It is proved, using so-called multirectangular invariants, that the condition αβ = α̃β̃ is sufficient for the isomorphism of the spaces $E₀(exp αi) ⊗̂ E_{∞}(exp βj)$ and $E₀(exp α̃i) ⊗̂ E_{∞}(exp β̃j)$. This solves a problem posed in [14, 15, 1]. Notice that the necessity has been proved earlier in [14].