| unique_al(ax0), unique_al(ay0 + (a × d)' + az), a0 ∈ ax0 ∨ a0 = a ↔ a0 ∈ az ∨ a0 = a ∨ a0 ∈ ay0, ∀ a0. a0 ∈ ax0 ∨ a0 = a ↔ a0 ∈ az ∨ a0 = a ∨ a0 ∈ ay0 ⊦ # ax0 = # ay0 + # az, a0 ∈ ax0 ↔ a0 ∈ ay0 ∨ a0 ∈ az, a ∈ ax0, a ∈ az |
a0 ∈ ay0 ∨ a0 ∈ az, unique_al(ax0), unique_al(ay0 + (a × d)' + az), a0 ∈ ax0 ∨ a0 = a ↔ a0 ∈ az ∨ a0 = a ∨ a0 ∈ ay0, ∀ a0. a0 ∈ ax0 ∨ a0 = a ↔ a0 ∈ az ∨ a0 = a ∨ a0 ∈ ay0 ⊦ a0 ∈ ax0, # ax0 = # ay0 + # az, a ∈ ax0, a ∈ az