| as ∩ range ri = ∅, key-cons(key, fs[ri[key]]), ri[key] ∈ fs, key ∈ ri ⊦ key-cons(key, (fs \ as)[ri[key]]) |
⊦ as = as0 ↔ (∀ adr. adr ∈ as ↔ adr ∈ as0)
key-cons(key, fs[ri[key]]), key ∈ ri, ri[key] ∈ fs, ∀ adr. adr ∈ as ∩ range ri ↔ adr ∈ ∅ ⊦ key-cons(key, (fs \ as)[ri[key]])
Used terms: ∅, as ∩ range ri