theorem Set.mem_powersettheorem Set.mem_powerset: ∀ {α : Type u} {x s : Set α}, x ⊆ s → x ∈ 𝒫 s
Published by @sam · Jul 21, 2026
View source in zpg9xh52
zpg9xh52
Definitional, with no premises to accept.
Set.mem_powerset
definitional fact