/**
 * @file License identifier constants. Exports common SPDX license strings (MIT,
 *   UNLICENSED) and a lazily-built set of copy-left SPDX identifiers used when
 *   classifying package licenses.
 */
export declare const MIT = "MIT";
export declare const UNLICENCED = "UNLICENCED";
export declare const UNLICENSED = "UNLICENSED";
/**
 * Get the set of SPDX identifiers considered copy-left (AGPL, GPL, EPL, EUPL,
 * CC-BY-SA variants). The set is lazily built and cached on first call.
 *
 * @returns A `Set` of SPDX license identifier strings.
 */
export declare function getCopyLeftLicenses(): Set<string>;
