| range ri ∩ as = ∅, ri-closed(ri, fs, ro) ⊦ ri-closed(ri, fs \ as, ro) |
range ri ∩ as = ∅, key ∈ ri, ∀ key. key ∈ ri → ri[key] ∈ fs ∧ node-closed(fs[ri[key]], ri, fs, ro) ⊦ ri[key] ∈ fs \ as ∧ node-closed((fs \ as)[ri[key]], ri, fs \ as, ro)
Used simplifier rules: ri-closed: ⊦ ri-closed(ri, fs, ro) ↔ (∀ key. key ∈ ri → ri[key] ∈ fs ∧ node-closed(fs[ri[key]], ri, fs, ro));