/** The chessboard file names. */
export declare const FILE_NAMES: readonly ["a", "b", "c", "d", "e", "f", "g", "h"];
/** The chessboard rank names. */
export declare const RANK_NAMES: readonly ["1", "2", "3", "4", "5", "6", "7", "8"];
/** The promotion piece names. */
export declare const PROMOTION_NAMES: readonly ["q", "r", "b", "n"];
/** A chessboard file name. */
export declare type FileName = typeof FILE_NAMES[number];
/** A chessboard rank name. */
export declare type RankName = typeof RANK_NAMES[number];
/** A promotion piece name. */
export declare type PromotionName = typeof PROMOTION_NAMES[number];
/**  A [long algebraic notation](https://en.wikipedia.org/wiki/Algebraic_notation_(chess)#Long_algebraic_notation) square. */
export declare type Square = `${FileName}${RankName}`;
/**
 * A [long algebraic notation](https://en.wikipedia.org/wiki/Algebraic_notation_(chess)#Long_algebraic_notation) move.
 *
 * @example
 *
 * ```
 * const move: UciMove = "e2e4q";
 * ```
 */
export declare type UciMove = `${Square}${Square}` | `${Square}${Square}${PromotionName}`;
/**
 * A protection state.
 *
 * @remarks Used in {@link RegistrationCommand} and {@link CopyProtectionCommand}.
 */
export declare type ProtectionState = "ok" | "error" | "checking";