| # ax0 = # ax1, ax0.toSet ⊆ range ri, ∀ key. key ∈ ri → ri[key] ∈ fs ∧ key-cons(key, fs[ri[key]]) ⊦ keys(fs, ax0).toSet ⊆ dom ri |
⊦ ks ⊆ ks0 ↔ (∀ key. key ∈ ks → key ∈ ks0)
# ax0 = # ax1, ax0.toSet ⊆ range ri, ∀ key. key ∈ ri → ri[key] ∈ fs ∧ key-cons(key, fs[ri[key]]) ⊦ ∀ key. key ∈ keys(fs, ax0).toSet → key ∈ dom ri
Used terms: dom ri, keys(fs, ax0).toSet