The uniformity of the meagre ideal is at most the rearrangement number #
Both cardinals have their literal definitions: nonM uses nonmeagre subsets
of the real line, and rr uses rearranging families of permutations of ℕ.
All preceding construction and category lemmas have been proved over mathlib.
theorem
NonMRR.exists_rearranging_family_of_cardinal_rr :
∃ (P : Set (Equiv.Perm ℕ)), IsRearranging P ∧ Cardinal.mk ↑P = rr
The defining minimum of the rearrangement number has an actual witness.
The uniformity of the meagre ideal on the real line is at most the rearrangement number. There are no additional hypotheses.