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Complete topos implies cocomplete - #444

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ScriptRaccoon merged 3 commits into
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dschepler:complete-topos-implies-cocomplete
Oct 30, 2026
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ScriptRaccoon merged 3 commits into
ScriptRaccoon:mainfrom
dschepler:complete-topos-implies-cocomplete

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@dschepler

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This adds several corollaries of the fact that in an elementary topos, the power object functor $T^{op} \to T$ is monadic and therefore creates limits, i.e. it creates colimits in T from limits in T. It came up in #362 as a convenient way to prove that since the effective topos doesn't have countable copowers, it also doesn't have countable powers.

@ScriptRaccoon ScriptRaccoon added the data additions and updates to the database label Oct 29, 2026
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Thanks for the PR. The changes are OK, I just have 4 minor comments.

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OK, I've addressed the comments in terms of grouping by limit type instead of by cardinalities, and adding some missing entries. I also added a few other missing entries I noticed while scanning the property list (regarding wide pullbacks and connected limits). I'll let you decide which ones you think are redundant, if any.

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ScriptRaccoon force-pushed the complete-topos-implies-cocomplete branch from d9fbf77 to 6454509 Compare October 30, 2026 08:37
Co-authored-by: Daniel Schepler <11821574+dschepler@users.noreply.github.com>
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ScriptRaccoon force-pushed the complete-topos-implies-cocomplete branch from 6454509 to fca861b Compare October 30, 2026 08:40
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ScriptRaccoon merged commit 8562616 into ScriptRaccoon:main Oct 30, 2026
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dschepler deleted the complete-topos-implies-cocomplete branch October 30, 2026 12:51
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