| # ax1 = # ax0, adr ∈ ri, ax1.toSet ⊆ range ri, # ax0 = # ax1 ∧ ax1.toSet ⊆ range ri ∧ (∀ key. key ∈ ri → ri[key] ∈ fs ∧ key-cons(key, fs[ri[key]])) → (key ∈ ri[keys(fs, ax1), ax1] ↔ key ∈ ri), ∀ key. key ∈ ri → ri[key] ∈ fs ∧ key-cons(key, fs[ri[key]]), key = fs[adr].key ∨ key ∈ keys(fs, ax1) ⊦ key ∈ ri |
# ax1 = # ax0, adr ∈ ri, ax1.toSet ⊆ range ri, ∀ key. key ∈ ri → ri[key] ∈ fs ∧ key-cons(key, fs[ri[key]]), key = fs[adr].key ∨ key ∈ keys(fs, ax1) ⊦ key ∈ ri, key ∈ ri[keys(fs, ax1), ax1]