⊦ ns ⊆ ns0 ↔ (∀ n. n ∈ ns → n ∈ ns0)
as.lebs ⊆ ns ⊦ (as -- adr).lebs ⊆ as.lebs, ∀ n. n ∈ (as -- adr).lebs → n ∈ ns
Used terms: ns, (as -- adr).lebs