| # x0 = # x1 + # x2, x0 + z = x1 + x2, n < # x0 ⊦ x0[n] = (x1 + x2)[n], x0 = [] |
⊦ x = y ↔ # x = # y ∧ (∀ n. n < # x → x[n] = y[n])
#(x0 + z) = #(x1 + x2), # x0 = # x1 + # x2, n < # x0, ∀ n. n < #(x0 + z) → (x0 + z)[n] = (x1 + x2)[n] ⊦ x0[n] = (x1 + x2)[n], x0 = []
Used terms: x1 + x2, x0 + z