/**
 * Whether an edge's two ends are nested one inside the other (#439, ADR 0139).
 *
 * Composition maps onto cytoscape's compound `parent`, so a pair that also
 * carries any OTHER relationship produces an edge from a container to its own
 * child. ELK cannot lay that out: measured on a five-concept model, the
 * container and its child render and every unrelated node loses its geometry.
 *
 * Its own module rather than a helper inside `graph-canvas.tsx`, following
 * `subject-filter.ts`: the canvas is type-checked with JSX and a test that
 * imports it is not, so pure rules live where a test can reach them.
 */
export declare function spansNesting(from: string, to: string, parentOf: ReadonlyMap<string, string>): boolean;