| ⊦ abs-keys(orphans(fs0, ri0)) = abs-keys(orphans(fs, ri)) ++ n ↔ orphans(fs0, ri0) = orphans(fs, ri) ++ inodekey(n) |
⊦ ks = ks0 ↔ (∀ key. key ∈ ks ↔ key ∈ ks0)
⊦ abs-keys(orphans(fs0, ri0)) = abs-keys(orphans(fs, ri)) ++ n ↔ (∀ key. key ∈ orphans(fs0, ri0) ↔ key ∈ orphans(fs, ri) ++ inodekey(n))
Used terms: orphans(fs, ri) ++ inodekey(n), orphans(fs0, ri0)