theorem Set.Subset.antisymm_ifftheorem Set.Subset.antisymm_iff: ∀ {α : Type u} {a b : Set α}, a = b ↔ a ⊆ b ∧ b ⊆ a
Published by @sam · Jul 21, 2026
View source in zpg9xh52
zpg9xh52
Definitional, with no premises to accept.
Set.Subset.antisymm_iff
definitional fact