-
Notifications
You must be signed in to change notification settings - Fork 297
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
[Merged by Bors] - feat(category_theory/limits): products give pullback squares #14327
Conversation
I'll do biproducts giving bicartesian squares shortly. |
def is_pushout_of_is_initial_is_coproduct {W X Y Z : C} (f : X ⟶ Z) (g : Y ⟶ Z) (h : W ⟶ X) | ||
(k : W ⟶ Y) (H₁ : is_terminal Z) | ||
(H₂ : is_limit (binary_fan.mk h k)) : | ||
is_limit (pullback_cone.mk _ _ (show h ≫ f = k ≫ g, from H₁.hom_ext _ _)) := | ||
(k : W ⟶ Y) (H₁ : is_initial W) | ||
(H₂ : is_colimit (binary_cofan.mk f g)) : | ||
is_colimit (pushout_cocone.mk _ _ (show h ≫ f = k ≫ g, from H₁.hom_ext _ _)) := |
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Apparently this had been copy-pasted ready for dualisation in #10581, but then only the declaration name was dualised!
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Thanks 🎉
bors merge
Merge conflict. |
bors merge |
Follow-up to #14220 Co-authored-by: Scott Morrison <scott.morrison@gmail.com>
Build failed: |
bors merge |
Follow-up to #14220 Co-authored-by: Scott Morrison <scott.morrison@gmail.com>
Pull request successfully merged into master. Build succeeded: |
Follow-up to #14220