Commit 2020-07-21 15:23 5776f4c0
View on Github →feat(topology): more lemmas about Ici and Iic neighborhoods (#3474)
Main feature : add tfae_mem_nhds_within_Ici
and tfae_mem_nhds_within_Iic
, analogous to the existing tfae_mem_nhds_within_Ioi
and tfae_mem_nhds_within_Iio
, as well as related lemmas (again imitating the open case)
I also added a few lemmas in data/set/intervals/basic.lean
that were useful for this and a few upcoming PRs