The ∂_zχ-carrying error term of eq:aniso:closure:mixed:bound is a plain constant #
mixedTermFactorDz's first summand carries ∂_zχ, hence is supported in a closed set A on
which the order-≤ 2 annulus data of lem:aniso:annulus bounds every factor: u_θ, ∂_r u_z
and ω_z, all read at the meridional representative, together with χ and ∂_zχ themselves,
which are globally bounded because χ is smooth with compact support. Multiplying these
uniform bounds by the (finite, time-independent) L¹ norm ∫ |χ| |∂_zχ| — rather than by the
measure of A, which need not be tracked — bounds the whole error integral by a constant that
does not depend on t.
The ∂_zχ-carrying error term of mixedTermFactorDz, weighted by u_θ at the
representative, is bounded by a plain constant: it is supported in A, where the order-≤ 2
annulus data bounds u_θ, ∂_r u_z and ω_z uniformly, and χ, ∂_zχ are globally bounded.