| ∀ a, b, d. a ∈ ax0[b, d] ↔ a = b ∨ a ∈ ax0 ⊦ a ∈ ((a0 × d0)' + ax0)[b, d] ↔ a = b ∨ a ∈ (a0 × d0)' ∨ a ∈ ax0 |
∀ a, b, d. a ∈ ax0[b, d] ↔ a = b ∨ a ∈ ax0 ⊦ a ∈ ((a0 × d0)' + ax0)[b, d] ↔ a = b ∨ a = a0 ∨ a ∈ ax0
Used simplifier rules: inone: ⊦ a ∈ (b × d0)' ↔ a = b;