English
For any X that carries a coalgebra structure over R, the counit on the CoalgCat object obtained via of X equals the original counit on X.
Русский
Для X сcoalgebra над R, кокнуция на объекте CoalgCat, полученном через of X, равна исходной кокнюйте на X.
LaTeX
$$$\\operatorname{Coalgebra}.counit( A := \\text{of } R X) = \\operatorname{Coalgebra}.counit( R := R)( A := X)$$$
Lean4
@[simp]
theorem of_counit {X : Type v} [AddCommGroup X] [Module R X] [Coalgebra R X] :
Coalgebra.counit (A := of R X) = Coalgebra.counit (R := R) (A := X) :=
rfl