import * as cg from 'chessgroundx/types';
import { Variant } from './chess';
export declare type MaterialDiff = Map<cg.PieceLetter, number>;
export declare function diff(lhs: MaterialDiff, rhs: MaterialDiff): MaterialDiff;
export declare function equivalentLetter(variant: Variant, letter: cg.PieceLetter): cg.PieceLetter;
export declare function calculateMaterialDiff(variant: Variant, fen?: string): MaterialDiff;
export declare function calculatePieceNumber(variant: Variant, fen?: string): MaterialDiff;
export declare function calculateGameImbalance(variant: Variant, fen: string): MaterialDiff;