| m ≤ # x0, ∀ m, a, b. m < # x0 → (a ∈ x0[m, b] ↔ a = b ∨ a ∈ x0 -1l x0[m]) ⊦ a ∈ (a0 ' + x0)[m, b] ↔ a = b ∨ a ∈ (a0 ' + x0) -1l (a0 ' + x0)[m] |
(a0 ' + x0)[m] = a0, m ≤ # x0, ∀ m, a, b. m < # x0 → (a ∈ x0[m, b] ↔ a = b ∨ a ∈ x0 -1l x0[m]) ⊦ a ∈ (a0 ' + x0)[m, b] ↔ a = b ∨ a ∈ (a0 ' + x0) -1l (a0 ' + x0)[m]
m ≤ # x0, ∀ m, a, b. m < # x0 → (a ∈ x0[m, b] ↔ a = b ∨ a ∈ x0 -1l x0[m]) ⊦ (a0 ' + x0)[m] = a0, a ∈ (a0 ' + x0)[m, b] ↔ a = b ∨ a ∈ (a0 ' + x0) -1l (a0 ' + x0)[m]
Used formulas: (a0 ' + x0)[m] = a0