import type { ArrayVector4D } from "./types.js";
/**
 * Calculates the angle between two 4D vectors.
 * @param {ArrayVector4D} xyzw1 - First vector as `[x, y, z, w]`
 * @param {ArrayVector4D} xyzw2 - Second vector as `[x, y, z, w]`
 * @param {number} [m1] - Optional magnitude of the first vector (default: `magnitude4D(xyzw1)`)
 * @param {number} [m2] - Optional magnitude of the second vector (default: `magnitude4D(xyzw2)`)
 * @returns {number} The angle in radians
 */
export declare const angleBetween4D: (xyzw1: ArrayVector4D, xyzw2: ArrayVector4D, m1?: number, m2?: number) => number;