import AbstractCalculator from './calculator'; declare class NumCalculator extends AbstractCalculator { result: number; constructor(num: number | string | AbstractCalculator); add(num: number | string | AbstractCalculator): this; sub(num: number | string | AbstractCalculator): this; mul(num: number | string | AbstractCalculator): this; div(num: number | string | AbstractCalculator): this; equal(): number; } export default NumCalculator;