Theorem 5.10. Assuming that:

  • AU be as above

  • J=ℕ

  • {C⊆ℕ:ℕ∖C is finite}⊆U

  • n∈ℕ

  • for each m∈ℕ, let Bm⊆An satisfying:

    • (1) [Bm]≠∅ ∀⁡m∈ℕ
    • (2) [Bk]⊆[Bm] for all m,k∈ℕ with m≤k

Then ⋂⁡m∈ℕ[Bm]≠∅.