A crux type, distinct from the gap register

Source: imported from the ChatGPT second opinion.

A crux is what would move the bottom line — necessarily verdict-relative, since a "would change the assessment if…" field presumes an assessment. This distinguishes it from a gap, which is what is not known (a neutral map-layer artifact).

Under the two-layer stance both belong, in different layers: gaps on the neutral map, cruxes attached to assessment artifacts. A crux carries its statement, why it matters, current evidence, possible resolutions, expected belief movement, and the cheapest next investigation — making the KB useful for deciding what to investigate next, not just what is known.