⊦ ⌜m + n⌝ = ⌜m⌝ + ⌜n⌝
⊦ ⌜n1⌝ + ⌜n⌝ + ⌜m⌝ = ⌜n2⌝ + ⌜n0 + n2⌝ ↔ n1 + n + m = n2 + n0 + n2
Used terms: n2, n0