mathlib
7362d50a - feat(topology/sheaves/sheaf_condition/opens_le_cover): generalize universe (#16214)

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3 years ago
feat(topology/sheaves/sheaf_condition/opens_le_cover): generalize universe (#16214) + Generalize universe levels in the sheaf condition `opens_le_cover` on topological spaces and its equivalence with the sheaf condition on sites, allowing three different universe parameters as in `Top.{w}`, `C : Type u` and `category.{v} C`. To be used in #15934. + Generalize universes for the sheaf condition `pairwise_intersection` on topological spaces. This sheaf condition also doesn't require any assumption on the category `C`, and its equivalence with `opens_le_cover` could also have universe levels at maximal generality; however, the proof `is_sheaf_opens_le_cover_iff_is_sheaf_pairwise_intersections` breaks due to the `small_category` restriction on [category_theory.functor.initial.is_limit_whisker_equiv](https://leanprover-community.github.io/mathlib_docs/category_theory/limits/final.html#category_theory.functor.initial.is_limit_whisker_equiv), which will take more work to fix, so we do not generalize the equivalence at this time. + Generalize universes for `Top.presheaf.pushforward`; pullback is not generalized because it would need `has_colimits_of_size`. `Top.sheaf.pushforward` is not yet generalized. + Fixate the universe level of [Top.presheaf](https://leanprover-community.github.io/mathlib_docs/topology/sheaves/presheaf.html#Top.presheaf) to be the same as [Top.sheaf](https://leanprover-community.github.io/mathlib_docs/topology/sheaves/sheaf.html#Top.sheaf).
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