Talk:Biproduct

A more accurate summary of the not-entirely-coherent spiel that I wrote here earlier might be: shouldn't we mention that biproducts can be defined in any semi-additive (i.e. commutative-monoid-enriched) category?

Puffinry 13:12, 24 April 2006 (UTC)

Top of page redirect
I've added this to redirect people looking for byproduct, which is commonly mis-spelt as biproduct or bi-product. I've copied the format of a page that also had a disambiguation page, but as this one doesn't have one and doesn't need one, so this leads to a dead link. If someone can fix this properly it'd be good.

HuttyMcphoo 23:43, 9 May 2007 (UTC)

Why is it called biproduct?
"Bi-" usually means something that is such-and-such in two ways, as in bilinear and bimodule. But why is it called biproduct in this case? I would like to know this, as I need to invent a Korean translation of this concept in order to write an article in .--Acepectif 20:27, 31 May 2007 (UTC)


 * It derives from the categorial point of view that it is both a product and a coproduct so it is a "product" in two senses (one the categorial dual of the other). -- Leland McInnes 03:00, 1 June 2007 (UTC)


 * Ah, I can't understand why I didn't find that it was already mentioned in the article. Anyway thanks! --Acepectif 05:02, 1 June 2007 (UTC)

Definition is wrong/incomplete
https://math.stackexchange.com/questions/967897/are-there-subtleties-in-the-definition-of-biproduct — Preceding unsigned comment added by Student298 (talk • contribs) 01:49, 8 October 2017 (UTC)


 * Thank you for pointing this out. Looking at the edit history for this article, Freeze S wrongly removed part of the definition in 2017, and his edit was never reverted. I have now repaired the definition. It baffles me how this article remained incorrect for almost three years. Joel Brennan (talk) 18:48, 16 April 2020 (UTC)

Mistake in the 'Properties' section
The second bullet point at the start of the 'Properties' section is problematic; $$p_l \circ f \circ i_k = 0$$ does not make sense unless we have zero morphisms, or at least a zero object. I have added a clarification tag to the article. Joel Brennan (talk) 18:27, 16 April 2020 (UTC)


 * Now that I have corrected the definition of a biproduct, the same point also applies to the condition $$p_l \circ i_k = 0$$ in the definition. Joel Brennan (talk) 18:51, 16 April 2020 (UTC)