6. Approximation by finite-width networks
Monte Carlo approximation turns a finite coefficient measure into a finite-width network. The Banach-valued Rademacher lemma precedes the general bound; a two-coordinate comparison then gives the dimension-free Lipschitz rate. We prove spectral moments and qualitative discretization before compact-open universality. The final subsection gives the Hilbert variance and vector rates. Appendix C records additional concentration and input-truncation consequences.