| key0 < key, key ∈ ri, key ∈ ri |≤ key1 ⊦ (ri |≤ key1)[key] = ((ri |> key0) |≤ key1)[key], key1 < key |
key0 < key, key ∈ ri ⊦ ri[key] = ((ri |> key0) |≤ key1)[key], key1 < key
Used simplifier rules: at-le: ⊦ ¬ key1 < key0 ∧ key0 ∈ ri → (ri |≤ key1)[key0] = ri[key0];%in-le: ⊦ key0 ∈ ri |≤ key1 ↔ key0 ∈ ri ∧ ¬ key1 < key0;