| adr ∈ ri ⊦ ∃ key. key ∈ ri \ ks ∧ (ri \ ks)[key] = adr, ∃ key. key ∈ ks ∧ key ∈ ri ∧ adr = ri[key] |
⊦ adr ∈ ri ↔ (∃ key. key ∈ ri ∧ ri[key] = adr)
∃ key. key ∈ ri ∧ ri[key] = adr ⊦ ∃ key. key ∈ ks ∧ key ∈ ri ∧ adr = ri[key], ∃ key. key ∈ ri \ ks ∧ (ri \ ks)[key] = adr
Used terms: ri, adr