English
The left-associated products are congruent in the quotient: x*(y*z*w) equals x*(y*(z*w)) in the quotient.
Русский
Лева-ассоциированное произведение эквивалентно в фактор-множество: \(x*(y*z*w)\) эквивалентно \(x*(y*(z*w))\).
LaTeX
$$$\\operatorname{Quot.mk}(\\operatorname{AssocRel}(\\alpha))(x \\ast (y \\ast z \\ast w)) = \\operatorname{Quot.mk}(\\operatorname{AssocRel}(\\alpha))(x \\ast (y \\ast (z \\ast w)))$$$
Lean4
@[to_additive]
theorem quot_mk_assoc_left (x y z w : α) : Quot.mk (AssocRel α) (x * (y * z * w)) = Quot.mk _ (x * (y * (z * w))) :=
Quot.sound (AssocRel.left _ _ _ _)