| ⊦ (σ to n) + σ0 to n1 + n = (σ to n) + (σ0 to n1), # σ0 < ⌜n1⌝ , # σ < ⌜n⌝ |
⊦ σ0 = σ1 ↔ # σ0 = # σ1 ∧ (∀ n. ⌜n⌝ < # σ0 → σ0[n] = σ1[n])
⊦ #((σ to n) + σ0 to n1 + n) = #((σ to n) + (σ0 to n1)) ∧ (∀ n0. ⌜n0⌝ < #((σ to n) + σ0 to n1 + n) → ((σ to n) + σ0 to n1 + n)[n0] = ((σ to n) + (σ0 to n1))[n0]), # σ0 < ⌜n1⌝ , # σ < ⌜n⌝
Used terms: (σ to n) + (σ0 to n1), (σ to n) + σ0 to n1 + n