English
The supremum of two congruences equals the smallest congruence containing the supremum of their underlying relations.
Русский
Супремум двух конгруэнций равен наименьшему конгруентному отношению, содержащему супремум их оснований.
LaTeX
$$$$ c \sqcup d = \operatorname{ringConGen}( \uparrow c \; \lor \; \uparrow d ) $$$$
Lean4
/-- The supremum of two congruence relations equals the smallest congruence relation containing
the supremum of the underlying binary operations. -/
theorem sup_def {c d : RingCon R} : c ⊔ d = ringConGen (⇑c ⊔ ⇑d) := by rw [sup_eq_ringConGen]; rfl