English
For any X that carries a coalgebra structure over R, the comultiplication on the CoalgCat object obtained via of X coincides with the original comultiplication on X.
Русский
Для X, имеющего структуру коалгебры над R, комультация на объекте CoalgCat, полученном через of X, совпадает с исходной комульятой на X.
LaTeX
$$$\\operatorname{Coalgebra}.comul( A := \\text{of } R X) = \\operatorname{Coalgebra}.comul( R := R)( A := X)$$$
Lean4
@[simp]
theorem of_comul {X : Type v} [AddCommGroup X] [Module R X] [Coalgebra R X] :
Coalgebra.comul (A := of R X) = Coalgebra.comul (R := R) (A := X) :=
rfl