Talk:Conjunction/disjunction duality

Copyright violations

This article is a mish-mash of text copied directly or almost directly from the sources it cites. For example, where the Internet Encyclopedia of Philosophy has this:

• Because of their semantics, i.e. the way they are standardly interpreted in CPL, these connectives can be defined in terms of each other, and consequently, only one of them needs to be taken as primitive.

This article has this:

• In classical propositional logic, the connectives for conjunction and disjunction can be defined in terms of each other, and consequently, only one of them needs to be taken as primitive.

Where Howson's textbook has this:

• So we have to establish that the following two conditions are satisfied: (1) each Ai has P; and (2) for any non-atomic X, from the inductive hypothesis that the immediate predecessors of X have P, it follows that X does also.

This article has this:

• So we have to establish that the following two conditions are satisfied: (1) each $A_{i}$ has $P$; and (2) for any non-atomic $X$, from the inductive hypothesis that the immediate predecessors of $X$ have $P$, it follows that $X$ does also. [sic]

This would have been a really nice contribution to Wikipedia, but alas. Botterweg (talk) 02:19, 24 September 2024 (UTC)

I've listed this at WP:CP, but that doesn't mean you can't clean up the infringing bits now. (And if the whole thing is copyvio of various sources, it's still valid for wholesale deletion.) -- asilvering (talk) 03:04, 24 September 2024 (UTC)

The article would need a near-total overhaul to remove the copyvio, but if the author is willing to fix it I think that would be an ideal outcome. Botterweg (talk) 22:47, 24 September 2024 (UTC)

The IEP text is incidental imo. The other thing is a mathematical proof, which is hard to paraphrase. If you think it's too close to the source then I think you can just remove the proof and leave the theorem without the proof. Thiagovscoelho (talk) 09:02, 24 September 2024 (UTC)

@Thiagovscoelho: A proof is easy to summarize if you understand it. And if you don't understand it yet, that's all the more reason to try. There is no better way of learning something than trying to reconstruct it for yourself, in your own words. On Wikipedia, it's obligatory to do so when the source is copyrighted and will also allow you to write better and more accessible articles. Sources may have viewpoints or pedagogical goals that aren't important for the average Wikipedia reader.

I have written a rough summary and proof of the Duality Theorem, but I will ask you to fix the rest of the article yourself. As your penance, I will also ask that you reformat and check over my work since I am running a somewhat high fever at the moment and it's likely I screwed something up. Botterweg (talk) 22:43, 24 September 2024 (UTC)