A fixed-width stream widens into a larger working space, every channel is judged for whether it matters right now, the judged result is brought back to the original width. The bar does the arguing: its width is the dimensionality, and judged channels visibly fade. The reader steps the stages by hand — an instrument, not a performance — and each stage carries its reading in the panel below, with an optional evidence-voice payoff line.
Promoted from vindex3.org's Anatomy chapter, where the stages are up_proj / gate_proj / the multiply / down_proj and the payoff lines are the container addresses those tensors answer to. The form knows none of that: stages, widths, and the kept-channel pattern are all the caller's.
THE INSTRUMENT’S DISCIPLINE
Every instrument carries an always-present text fallback, so the point survives with the interaction removed — for reduced motion, for no-JS, for a crawler, and for anyone in a hurry. ARIA state is part of the form, because an agent browser reads aria-pressed and aria-expanded to understand what it is looking at.