| # ax0 = # ax, ri-cons(ri, fs), ax0.toSet ⊆ range ri ⊦ key ∈ ri[keys(fs, ax0), ax] ↔ key ∈ ri |
# ax0 = # ax, ax0.toSet ⊆ range ri, ∀ key. key ∈ ri → ri[key] ∈ fs ∧ key-cons(key, fs[ri[key]]) ⊦ key ∈ ri[keys(fs, ax0), ax] ↔ key ∈ ri
Used simplifier rules: ri-cons: ⊦ ri-cons(ri, fs) ↔ (∀ key. key ∈ ri → ri[key] ∈ fs ∧ key-cons(key, fs[ri[key]]));