English
For hab: a = b and hbc: b = c, the composition (ringEquivCongr hab).trans (ringEquivCongr hbc) equals ringEquivCongr (hab.trans hbc).
Русский
Для несоответствий hab и hbc выполняется композиция кольцевых изоморфизмов равна ringEquivCongr (hab.trans hbc).
LaTeX
$$$ (ringEquivCongr hab).trans (ringEquivCongr hbc) = ringEquivCongr (hab.trans hbc) $$$
Lean4
theorem ringEquivCongr_trans {a b c : ℕ} (hab : a = b) (hbc : b = c) :
(ringEquivCongr hab).trans (ringEquivCongr hbc) = ringEquivCongr (hab.trans hbc) :=
by
subst hab hbc
cases a <;> rfl