theorem Set.mem_sInter._simp_1
theorem Set.mem_sInter._simp_1
: ∀ {α : Type u} {x : α} {S : zpg9xh52.Set (zpg9xh52.Set α)},
  Membership.mem (zpg9xh52.Set.sInter S) x = ∀ (t : zpg9xh52.Set α), Membership.mem S t → Membership.mem t x