leanprover-community / leanprover-community/mathlib4
Missing `positivity` extensions
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t-meta
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Description
The following extensions are still missing:
-
EReal(Mathlib/Data/Real/EReal.lean) - powers on
ℝ≥0andℝ≥0∞(Mathlib/Analysis/SpecialFunctions/Pow/NNReal.lean) -
Finset.card(Mathlib/Data/Fintype/Card.lean) -
•(Algebra.Order.SMul) -
Real.sqrt/NNReal.sqrt(Data.Real.Sqrt). There are two extensions, but they are currently broken - ... probably more
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 by reviewing the existing positivity extensions and the listed locations: Mathlib/Data/Real/EReal.lean, Mathlib/Analysis/SpecialFunctions/Pow/NNReal.lean, Algebra.Order.SMul, and Data.Real.Sqrt. Check the two marked sqrt extensions because the issue says they are broken. Done means the remaining listed extensions are implemented, the broken sqrt extensions work, and any additional missing extensions are identified.
Written by the indexing model from the issue text.
Assessment
- Domain
- devtools
- Issue type
- Feature
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 30/100