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Towers of category constructors
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Terminology: `IsDistributiveCategory` vs. `IsDistributiveBicartesianCategory` #245

Closed zickgraf closed 1 year ago

zickgraf commented 1 year ago

I have seen on nLab that IsDistributiveCategory is standard terminology for a bicartesian category with a distributivity law for products and coproducts. I would still suggest to call it IsDistributiveBicartesianCategory in CAP to avoid confusion ~, especially if we later introduce IsDistributiveMonoidalCategory. Otherwise it would be very easy to confuse IsMonoidalCategory and IsDistributiveCategory and IsDistributiveMonoidalCategory, i.e. assume an implication in at least one direction~.

mohamed-barakat commented 1 year ago

I have seen on nLab that IsDistributiveCategory is standard terminology for a bicartesian category with a distributivity law for products and coproducts. I would still suggest to call it IsDistributiveBicartesianCategory in CAP to avoid confusion, especially if we later introduce IsDistributiveMonoidalCategory. Otherwise it would be very easy to confuse IsMonoidalCategory and IsDistributiveCategory and IsDistributiveMonoidalCategory, i.e. assume an implication in at least one direction.

IsDistributiveMonoidalCategory only makes sense if we know over what the tensor product distributes. In case of the direct sum we already call it "additive monoidal categories". However, we did not introduce the corresponding and-filter.

zickgraf commented 1 year ago

IsDistributiveMonoidalCategory only makes sense if we know over what the tensor product distributes.

nLab says: "A distributive monoidal category is a monoidal category whose tensor product distributes over coproducts." But indeed it also mentions that "this is not entirely standard terminology".

In case of the direct sum we already call it "additive monoidal categories". However, we did not introduce the corresponding and-filter.

Which and-filter do you mean?

mohamed-barakat commented 1 year ago

In case of the direct sum we already call it "additive monoidal categories". However, we did not introduce the corresponding and-filter.

Which and-filter do you mean?

IsAdditiveMonoidalCategory. I believe we did not introduce it since a monoidal structure on an additive category does not necessarily distribute over the direct sum. E.g., the direct sum as a monoidal structure does not distribute over itself.

mohamed-barakat commented 1 year ago

The terminology IsDistributiveMonodialCategory on nLab is biased towards coproduct.

zickgraf commented 1 year ago

I still find IsDistributiveCategory confusing (independent of the existence and/or definition of IsDistributiveMonodialCategory) and would suggest naming it IsDistributiveBicartesianCategory. However, if you think IsDistributiveCategory is generally understood, feel free to close the issue.

mohamed-barakat commented 1 year ago

What about making IsDistributiveBicartesianCategory a synonym? We can wait until Julia supports DeclareSynonym.

zickgraf commented 1 year ago

Would IsDistributiveBicartesianCategory be a synonym of IsDistributiveCategory or the other way round? I.e. would Display( IsDistributiveBicartesianCategory ) print

<Property "IsDistributiveCategory">

or

<Property "IsDistributiveBicartesianCategory">

?

mohamed-barakat commented 1 year ago

Display( IsDistributiveBicartesianCategory ) would print IsDistributiveCategory.

zickgraf commented 1 year ago

Display( IsDistributiveBicartesianCategory ) would print IsDistributiveCategory.

I think this would be even more confusing :D I will close the issue.