Symmetric_Difference_is_Associative
Provedproofwikisymmetric-difference
Symmetric difference is associative: R △ (S △ T) = (R △ S) △ T
Preamble
import Mathlib.Order.SymmDiff import Mathlib.Data.Set.Basic
Formal statement
theorem Symmetric_Difference_is_Associative {α : Type _} (R S T : Set α) : symmDiff R (symmDiff S T) = symmDiff (symmDiff R S) T := by sorrySource