leanprover-community / leanprover-community/mathlib4
Define a typeclass for GO-space
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t-topology
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Description
The definition of a GO-space can be found here: https://topology.pi-base.org/properties/P000154
Also prove the following lemmas:
- A linearly ordered space is a GO-space.
- A separable GO-space is hereditarily separable.
- Optional: other lemmas that you can find on https://topology.pi-base.org/properties/P000154.
This is mentioned in https://github.com/leanprover-community/mathlib4/pull/41918.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with the GO-space definition at the linked pi-Base property and review the linked pull request for relevant mathlib context. Then inspect existing topology typeclasses and proofs in the surrounding mathlib area; done means a GO-space typeclass and proofs of the two required lemmas, with any optional results clearly separated.
Written by the indexing model from the issue text.
Assessment
- Domain
- devtools
- Issue type
- Feature
- Difficulty
- 5/5
- Estimated time
- Over a week
- Activity status
- Quiet
- Clarity
- Mostly clear
- Newbie friendliness
- 48/100