| tree[p] = dnode(md, sdt) ⊦ tree.dir? ∧ p ∈ tree → (q ∈ tree[p, dnode(md, sdt[str, tree0])] ↔ (p + str ' ⊑ q ⊃ restn(# p + 1, q) ∈ tree0;q ∈ tree)) |
tree[p] = dnode(md, sdt), tree.dir?, p ∈ tree ⊦ q ∈ tree[p, dnode(md, sdt[str, tree0])] ↔ (p + str ' ⊑ q ⊃ restn(# p + 1, q) ∈ tree0;q ∈ tree)