leanprover-community / leanprover-community/mathlib4
refactor: add TC cycles
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Description
In Lean 3, many lemmas are not instances to avoid loops. I think that we should not turn them into instances while porting. Instead, we should turn them into instances all at once after the port is done and see how does it affect build time. For now, we should create a list of these lemmas.
-
normalOfCompactT2; -
T3Space.mk(any T₀ regular space is a T₃ space); -
normalSpaceOfT3SecondCountable; -
compact_t2_tot_disc_iff_tot_sep(theIff.mpimplication); -
loc_compact_t2_tot_disc_iff_tot_sep; -
UniformSpace.secondCountable_of_separable
Contributor guide
First steps
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Research direction
No files or tests are named. Start by locating the definitions and existing instance declarations for the six listed lemmas, then review how their typeclass relationships could create cycles. Done means the checklist is complete and the port preserves the intended non-instance declarations until the post-port evaluation.
Written by the indexing model from the issue text.
Assessment
- Domain
- tooling
- Issue type
- Refactor
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 25/100