Intervals as finsets #
THIS FILE IS SYNCHRONIZED WITH MATHLIB4. Any changes to this file require a corresponding PR to mathlib4.
This file provides basic results about all the finset.Ixx, which are defined in
order.locally_finite.
TODO #
This file was originally only about finset.Ico a b where a b : ℕ. No care has yet been taken to
generalize these lemmas properly and many lemmas about Icc, Ioc, Ioo are missing. In general,
what's to do is taking the lemmas in data.x.intervals and abstract away the concrete structure.
Complete the API. See https://github.com/leanprover-community/mathlib/pull/14448#discussion_r906109235 for some ideas.
Alias of the reverse direction of finset.Icc_eq_empty_iff.
Alias of the reverse direction of finset.Ico_eq_empty_iff.
Alias of the reverse direction of finset.Ioc_eq_empty_iff.
A set with upper and lower bounds in a locally finite order is a fintype
Equations
- set.fintype_of_mem_bounds ha hb = (set.Icc a b).fintype_subset _
finset.cons version of finset.Ico_insert_right.
finset.cons version of finset.Ioc_insert_left.
finset.cons version of finset.Ioo_insert_right.
finset.cons version of finset.Ioo_insert_left.
finset.cons version of finset.Ioi_insert.
finset.cons version of finset.Iio_insert.
A sort of triangle inequality.