⊦ adr ∈ ri ↔ (∃ key. key ∈ ri ∧ ri[key] = adr)
ri-cons(ri, nodes(gstore, ginval)), key ∈ ri, ∃ key0. key0 ∈ ri -- key ∧ (ri -- key)[key0] = ri[key] ⊦
Used terms: ri -- key, ri[key]