leanprover-community / leanprover-community/mathlib4
Feature Request: Attribute to map rewrite rules through a functor
Open
Nobody has claimed this yet.
- Dominant language
- Lean
- Stars
- 4.2k
- Forks
- 1.7k
- PR merge metrics
- No merged PRs in 30d
Description
Zulip discussion: #Is there code for X? > Attribute to map rewrite rules through a functor?
I am requesting an attribute to tag on a lemma of the form
@[map] lemma f_comp_g : f ≫ g = h := sorry
to automatically generate a lemma of the form:
F.map f ≫ F.map g = F.map h
and potentially other similar lemmas (e.g. applying the function for concrete categories).
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 linked Zulip discussion and the requested @[map] lemma example. Clarify the intended generated forms, including F.map and applications to concrete categories; done means the supported attribute behavior and its scope are defined and implemented.
Written by the indexing model from the issue text.
Assessment
- Domain
- tooling
- Issue type
- Feature
- Difficulty
- 5/5
- Estimated time
- Over a week
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 25/100