/**
 * Return the symmetric difference across a list of UTC intervals — the set of instants covered
 * by an odd number of the input intervals.
 *
 * - List-form generalization of `intervalXorUtc`, which is pairwise only.
 * - Implemented as a coverage sweep: each interval contributes a `+1` at its start and a `-1`
 *   one nanosecond after its end; the result is every maximal run where the running coverage
 *   count is odd. For two intervals this reduces to exactly `intervalXorUtc`'s pairwise result.
 * - Order of the input list does not matter; the result is sorted by start.
 * - Returns `[]` for an empty list, and `[]` when every instant is covered an even number of
 *   times (e.g. two identical intervals cancel out).
 * - Returns `[]` when `intervals` is not an array, when any element is not a
 *   `{ start, end }` record of valid ISO UTC datetime strings, or when any element has
 *   `start > end` or a leap-second string.
 *
 * @param intervals array of `{ start, end }` records
 * @returns array of `{ start, end }` records covered an odd number of times, or `[]` on invalid input
 *
 * @example intervalXorAllUtc([{ start: "2024-01-01T00:00:00Z", end: "2024-01-10T00:00:00Z" }, { start: "2024-01-05T00:00:00Z", end: "2024-01-15T00:00:00Z" }]) // [{ start: "2024-01-01T00:00:00Z", end: "2024-01-04T23:59:59.999999999Z" }, { start: "2024-01-10T00:00:00.000000001Z", end: "2024-01-15T00:00:00Z" }]
 * @example intervalXorAllUtc([]) // []
 */
export declare function intervalXorAllUtc(intervals: Array<{
    start: string;
    end: string;
}>): Array<{
    start: string;
    end: string;
}>;