| ax.toSet = range ri | n, ri[key] = @(n, m0, m1), ri-cons(ri, fs), key ∈ ri ⊦ ∃ adr. adr ∈ ax ∧ fs[adr].key = key |
⊦ key ∈ ri ↔ (∃ adr, ri0. ri = ri0[key, adr] ∧ ¬ key ∈ ri0)
ax.toSet = range ri | n, ri[key] = @(n, m0, m1), ri-cons(ri, fs), ∃ adr, ri0. ri = ri0[key, adr] ∧ ¬ key ∈ ri0 ⊦ ∃ adr. adr ∈ ax ∧ fs[adr].key = key
Used terms: ri, key