| tree[p] = fnode(fid), p ∈ tree ⊦ fid ∈ tree.fids |
⊦ fnode(fid).fids = {fid}
tree[str + p0] = fnode(fid), str + p0 ∈ tree, ∀ tree, fid. tree[p0] = fnode(fid) ∧ p0 ∈ tree → fid ∈ tree.fids ⊦ fid ∈ tree.fids
Used simplifier rules: fids-fnode: ⊦ fnode(fid).fids = {fid} ;%path freely generated by ε, +;;% ⊦ tree[ε] = tree; (s)% ⊦ ε ∈ tree; (s)% ⊦ fid ∈ {fid0} ↔ fid = fid0; (s)