English
The pushout of the two algebra maps is realized by the algebra A ⊗_R B with the canonical maps from A and B into the tensor product.
Русский
Пуш-аут двух алгебраических отображений реализуется через алгебру \(A\\otimes_R B\) с каноническими отображениями из A и B.
LaTeX
$$$\\text{IsPushout}(\\text{ofHom}(\\text{algebraMap }R S),\\ldots)$ with tensor product structure$$
Lean4
theorem isPushout_tensorProduct (R A B : Type u) [CommRing R] [CommRing A] [CommRing B] [Algebra R A] [Algebra R B] :
IsPushout (ofHom <| algebraMap R A) (ofHom <| algebraMap R B)
(ofHom (S := A ⊗[R] B) <| Algebra.TensorProduct.includeLeftRingHom)
(ofHom (S := A ⊗[R] B) <| Algebra.TensorProduct.includeRight.toRingHom)
where
w := by
ext
simp
isColimit' := ⟨pushoutCoconeIsColimit R A B⟩