/**
 * missingContext — interface #3: find context that was AVAILABLE but never
 * reached the model (RFC-003).
 *
 * The localizer's influence ranking (#1) + ablation (#2) handle culprits that
 * are PRESENT in the context. They are blind to the opposite failure: a needed
 * unit that was *dropped* — truncated out of the window, or never selected —
 * so the model never saw it. You cannot ablate what isn't there.
 *
 * This finder is the cheap, exact, deterministic half of that case: a SET
 * DIFFERENCE over unit ids. The library tracks context as identified units
 * (each injection / memory entry / tool result has a stable id), so "what got
 * dropped" is `available − sent` — no embeddings, no LLM, O(n).
 *
 * Causal confirmation is the MIRROR of ablation: RESTORATION. Add a dropped
 * unit back, re-run, and an outcome flip is the causal proof. Like ablation,
 * the re-run is consumer-supplied (the library doesn't own your agent loop);
 * see `findDroppedContext` docs + example 10 for the pattern.
 *
 * Honest claim: a dropped unit is a CANDIDATE missing-context culprit, never a
 * confirmed cause — most dropped context is correctly dropped. Only restoration
 * makes a causal claim.
 */
/** One unit of context, identified by a stable id (injection id, memory id,
 *  tool-result id, ...). `content` is optional — carried through for display
 *  and for the restoration re-run. */
export interface ContextUnit {
    readonly id: string;
    readonly content?: string;
}
/** A unit that was available for the turn but never reached the model. */
export interface DroppedUnit {
    readonly id: string;
    readonly content?: string;
}
export interface MissingContextResult {
    /**
     * Units available for the turn that did NOT reach the model (`available −
     * sent`, matched by id, input order preserved). Each is a CANDIDATE
     * missing-context culprit — confirm by restoration, never assume.
     */
    readonly dropped: readonly DroppedUnit[];
    /** Distinct available units considered. */
    readonly availableCount: number;
    /** Distinct sent units that reached the model. */
    readonly sentCount: number;
    /** True when anything was dropped — a missing-context bug is possible. */
    readonly anyDropped: boolean;
    /** Human-readable explanation. PRESENTATION ONLY — read `dropped` /
     *  `anyDropped` as data, never parse this string. */
    readonly reason: string;
}
/**
 * Find context that was available for a turn but never reached the model —
 * `available − sent` by id. Pure, deterministic, O(n); no model or embedder.
 *
 * Ids are assumed stable and unique per side (duplicates are de-duplicated,
 * first occurrence wins). Units in `sent` but not `available` are ignored.
 *
 * Confirm a candidate causally by RESTORATION (the mirror of ablation): add the
 * dropped unit back into the context and re-run; an outcome flip is the proof.
 *
 * @example
 *   const { dropped, anyDropped } = findDroppedContext(assembled, sentToModel);
 *   if (anyDropped) {
 *     for (const unit of dropped) {
 *       if (await rerunWith(unit).outcomeFlips()) report(unit); // restoration = causal
 *     }
 *   }
 */
export declare function findDroppedContext(available: readonly ContextUnit[], sent: readonly ContextUnit[]): MissingContextResult;