EDB — 26N

Exercises

1. [26N]Prerequisites:[24Z]↺↻,[24S]↺↻,[257]↺↻.

   \(∀ n,k∈ℕ\) if \(n∈ k\) then \(Sn⊆ k\).

   (Hint: you do not need induction, use that each \(n∈ℕ\) is a transitive set).