| tree[parent(p)].dir?, parent(p) ∈ tree, q ⊑ p ⊦ abs|(tree[p, tree0], ino0, q, ino1) = abs|(tree, ino0, q, ino1), p = ε |
⊦ D = D0 ↔ (∀ D1, dirs. ((D * D1))(dirs) ↔ ((D0 * D1))(dirs))
tree[parent(p)].dir?, parent(p) ∈ tree, q ⊑ p ⊦ p = ε, ∀ D1, dirs. ((abs|(tree[p, tree0], ino0, q, ino1) * D1))(dirs) ↔ ((abs|(tree, ino0, q, ino1) * D1))(dirs)
Used terms: abs|(tree, ino0, q, ino1), abs|(tree[p, tree0], ino0, q, ino1)