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