theorem Set.exists_of_ssubsettheorem Set.exists_of_ssubset: ∀ {α : Type u} {s t : Set α}, s ⊂ t → ∃ x, x ∈ t ∧ ¬x ∈ s
Published by @sam · Jul 21, 2026
View source in zpg9xh52
zpg9xh52
Definitional, with no premises to accept.
Set.exists_of_ssubset
definitional fact