[Merged by Bors] - chore: use notation3 for Ordinal.typeLT

[vihdzp]

This creates a delaborator, which avoids goals from looking like (type fun x1 x2 ↦ x1 < x2) < (type fun x1 x2 ↦ x1 < x2).

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[github-actions]

PR summary d21f60a088

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

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Declarations diff

No declarations were harmed in the making of this PR! 🐙

You can run this locally as follows

## from your `mathlib4` directory:
git clone https://github.com/leanprover-community/mathlib-ci.git ../mathlib-ci

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

## more verbose report:
../mathlib-ci/scripts/pr_summary/declarations_diff.sh long <optional_commit>

The doc-module for scripts/pr_summary/declarations_diff.sh in the mathlib-ci repository contains some details about this script.

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No changes to strong technical debt.

No changes to weak technical debt.

[YaelDillies]

Can you write a test with #guard_msgs?

[vihdzp]

Where should that test go? Directly below the notation? In a new file?

[YaelDillies]

Directly below is okay

[YaelDillies]

Thanks! 🚀

maintainer merge

[github-actions]

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

[riccardobrasca]

Thanks!

bors merge

[mathlib-bors]

Pull request successfully merged into master.

Build succeeded:

• ci (staging) / Post-Build Step
• ci (staging) / Lint style
• ci (staging) / Build
• ci (staging) / Post-CI job