| key ∈ ro ⊦ (ri \ datakeys(key, n, ri)) ⊖ ro = ri ⊖ ro |
key ∈ ro ⊦ # ro = 0, ro = ∅, (ri \ datakeys(key, n, ri)) ⊖ ro = ri ⊖ ro
Used simplifier rules: size-zero-01: ⊦ ks ≠ ∅ → # ks ≠ 0; (forward) from specification set-basic[node-index]%ne-01: ⊦ key ∈ ks → ks ≠ ∅; (forward) from specification set-basic[node-index]