/** Its own module because `table.tsx`, `shape_frame.tsx` and `card_grid.tsx` ask it and may not import
 *  each other. Each draws a label over the reading, and a label over nothing (`Revenue · 0 ₫` down twenty
 *  rows) states silence; a column under its own heading is different, where zero is the answer. */
/** A value, never the node drawn for it, which cannot be asked what it says. */
export type Reading = string | number | null | undefined;
/** Unstated, empty, or zero; a caller with no reading passes `undefined`. */
export declare function saysNothing(value: Reading): boolean;