English
The quotient map respects associativity: the quotient of x*y*z equals the quotient of x*(y*z).
Русский
Квази-отношение сохраняет ассоциативность: образ по отношению к \(x*y*z\) равен образу к \(x*(y*z)\).
LaTeX
$$$\\operatorname{Quot.mk}(\\operatorname{AssocRel}(\\alpha))(x \\ast y \\ast z) = \\operatorname{Quot.mk}(\\operatorname{AssocRel}(\\alpha))(x \\ast (y \\ast z))$$$
Lean4
@[to_additive]
theorem quot_mk_assoc (x y z : α) : Quot.mk (AssocRel α) (x * y * z) = Quot.mk _ (x * (y * z)) :=
Quot.sound (AssocRel.intro _ _ _)