| unique_al(ax0 -1l (a0 × d0)), unique_al(ax0 -1l (a0 × d0)) → a0 ∈ ax0 -1l (a0 × d0) ∨ unique_al(ax0) ⊦ a0 × d0 = a × d, a0 = a, a ∈ ax0 -1l (a0 × d0), ¬ a ∈ ax0 ∧ unique_al(ax0), a0 ∈ ax0 -1l (a0 × d0) |
unique_al(ax0 -1l (a0 × d0)), unique_al(ax0), a ∈ ax0 ⊦ a0 × d0 = a × d, a0 = a, a ∈ ax0 -1l (a0 × d0), a0 ∈ ax0 -1l (a0 × d0)