theorem Set.Subset.transtheorem Set.Subset.trans: ∀ {α : Type u} {a b c : Set α}, a ⊆ b → b ⊆ c → a ⊆ c
Published by @sam · Jul 21, 2026
View source in zpg9xh52
zpg9xh52
Definitional, with no premises to accept.
Set.Subset.trans
definitional fact