| str ∈ sdt, p0 ∈ sdt[str], ∀ tree. p0 ∈ tree → (tree -- p0).fids = tree.fids \ tree[p0].fids ∨ p0 = ε ⊦ (dnode(md, sdt) -- (str ' + p0)).fids = sdt.fids \ sdt[str][p0].fids |
⊦ str ∈ sdt ↔ (∃ tree, sdt0. sdt = sdt0[str, tree] ∧ ¬ str ∈ sdt0)
p0 ∈ sdt[str], ∀ tree. p0 ∈ tree → (tree -- p0).fids = tree.fids \ tree[p0].fids ∨ p0 = ε, ∃ tree, sdt0. sdt = sdt0[str, tree] ∧ ¬ str ∈ sdt0 ⊦ (dnode(md, sdt) -- (str ' + p0)).fids = sdt.fids \ sdt[str][p0].fids
Used terms: sdt, str