English
The comultiplication on the tensor object equals the comul on the tensor product structure, respecting the coalgebra structure on the tensor product.
Русский
Коалгебраическая комулляция на тензорном объекте равна комулу на структуре тензорного произведения, сохраняющая коалгебраическую структуру тензорного произведения.
LaTeX
$$$$ Coalgebra.comul (R := R) (A := (K ⊗ L : CoalgCat R)) = Coalgebra.comul (A := K ⊗[R] L). $$$$
Lean4
theorem comul_tensorObj :
Coalgebra.comul (R := R) (A := (CoalgCat.of R M ⊗ CoalgCat.of R N : CoalgCat R)) =
Coalgebra.comul (A := M ⊗[R] N) :=
by
rw [ofComonObjCoalgebraStruct_comul]
simp [tensorμ_eq_tensorTensorTensorComm, TensorProduct.comul_def, AlgebraTensorModule.tensorTensorTensorComm_eq]
rfl