leanprover-community / leanprover-community/mathlib4
Nonexistent `SetRel.map` in example
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Description
SetRel.map is given as an example in the SetRel documentation, but this function is undefined. Three possible remedies
- Define
SetRel.map, - Update the example to use an existing function, or
- Remove the example altogether.
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 SetRel documentation example in Mathlib/Data/Rel.lean at lines 51–52 and verify whether SetRel.map is defined elsewhere. Resolve the example by defining the missing function, replacing it with an existing function, or removing the example, then confirm the documentation no longer refers to an undefined function.
Written by the indexing model from the issue text.
Assessment
- Domain
- documentation
- Issue type
- Documentation
- Difficulty
- 2/5
- Estimated time
- 1-3 hours
- Activity status
- Quiet
- Clarity
- Mostly clear
- Newbie friendliness
- 65/100