The fifteen lower bounds Rlow k ≤ ρ_{a₋}(x_{k+1}), one declaration per point.
The upstream comments attribute the data (sl ≤ s ≤ sh, P, m) to
tools/b2_numerics.py, which is not distributed upstream. The exact inputs and a replacement
rational reproduction procedure are documented in CertificateReproduction.lean. Each
side goal is a small norm_num on rationals. U₁ ≤ 211761/100000, U₅ ≥ 266853/50000.