| ⊦ σ from m from n = σ from m + n, # σ < ⌜m + n⌝ |
⊦ σ from m from n = σ from m + n, # σ < ⌜m⌝ + ⌜n⌝
Used simplifier rules: c: ⊦ m + n = n + m; from specification nat-basic%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic% ⊦ ⌜m + n⌝ = ⌜m⌝ + ⌜n⌝ ; (s)