| ⊦ (n < # x + # x0 ⊃ (x + x0)[n];nf(n - # x + # x0)) = (n < # x ⊃ x[n];(n < # x0 + # x ⊃ x0[n - # x];nf(n - # x - # x0))) |
n < # x + # x0 ⊦ (x + x0)[n] = (n < # x ⊃ x[n];(n < # x0 + # x ⊃ x0[n - # x];nf(n - # x - # x0)))
¬ n < # x + # x0 ⊦ nf(n - # x + # x0) = (n < # x ⊃ x[n];(n < # x0 + # x ⊃ x0[n - # x];nf(n - # x - # x0)))