HiPPO theory: orthogonal-basis projection operators
Legendre/Laguerre/Fourier bases; optimal polynomial approximation of input history.
HiPPO theory: orthogonal-basis projection operators
This chapter is planned. See the chapter-at-a-glance (foundations §3) for the full design; the crosswalk (foundations §22) maps this chapter to the relevant post_transformers/roadmap.md weeks.