| str + p0 ∈ tree, ∀ tree. p0 ∈ tree → tree[p0].fids ⊆ tree.fids ⊦ tree[str + p0].fids ⊆ tree.fids |
str ' ∈ tree, p0 ∈ tree[str '], ∀ tree. p0 ∈ tree → tree[p0].fids ⊆ tree.fids ⊦ tree[str ' + p0].fids ⊆ tree.fids
Used simplifier rules: a: ⊦ (p + p0) + p1 = p + p0 + p1; from specification list[path]% ⊦ p + q ∈ tree ↔ p ∈ tree ∧ q ∈ tree[p]; (s)% ⊦ str + p = str ' + p; (s)