[Merged by Bors] - feat(Order/Nucleus): nuclei form a complete lattice

[Bergschaf]

Arbitrary meets of nuclei can be defined pointwise. Joins are harder to describe explicitely, so completeLatticeOfCompleteSemilatticeInf is used to create the CompleteLattice instance.

---

[github-actions]

PR summary 76b084dd70

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

---

Declarations diff

+ iInf_apply
+ instance : CompleteLattice (Nucleus X) := completeLatticeOfCompleteSemilatticeInf (Nucleus X)
+ instance : CompleteSemilatticeInf (Nucleus X)
+ instance : InfSet (Nucleus X)
+ monotone
+ sInf_apply

You can run this locally as follows

## summary with just the declaration names:
./scripts/declarations_diff.sh <optional_commit>

## more verbose report:
./scripts/declarations_diff.sh long <optional_commit>

The doc-module for script/declarations_diff.sh contains some details about this script.

---

No changes to technical debt.

You can run this locally as

./scripts/technical-debt-metrics.sh pr_summary

• The relative value is the weighted sum of the differences with weight given by the inverse of the current value of the statistic.
• The absolute value is the relative value divided by the total sum of the inverses of the current values (i.e. the weighted average of the differences).

[YaelDillies]

Nice work! I think this can be golfed

[YaelDillies]

I pushed a final golf. LGTM, thanks! 🚀

maintainer merge

[github-actions]

🚀 Pull request has been placed on the maintainer queue by YaelDillies.

[jcommelin]

Thanks 🎉

bors merge

[mathlib-bors]

Pull request successfully merged into master.

Build succeeded:

• Build
• Lint style