| key ∈ ro ⊦ # ro = 0, ro = ∅, (ri \ datakeys(key, n, ri)) ⊖ ro = ri ⊖ ro |
⊦ ri = ri0 ↔ (∀ key. (key ∈ ri ↔ key ∈ ri0) ∧ (key ∈ ri → ri[key] = ri0[key]))
key ∈ ro ⊦ # ro = 0, ro = ∅, ∀ key0. (key0 ∈ (ri \ datakeys(key, n, ri)) ⊖ ro ↔ key0 ∈ ri ⊖ ro) ∧ (key0 ∈ (ri \ datakeys(key, n, ri)) ⊖ ro → ((ri \ datakeys(key, n, ri)) ⊖ ro)[key0] = (ri ⊖ ro)[key0])
Used terms: ri ⊖ ro, (ri \ datakeys(key, n, ri)) ⊖ ro