import { Config } from './config';
import { IFormula } from './i-formula';
export declare class FormulaBuilder {
    private config;
    constructor(config: Config);
    generateFormula(): IFormula;
    private generateFormulaChunks;
    /**
     * Returns formula in classic presentation
     * @example 5 + 1 = ?
     * @param {String[]} formula
     * @param {Number} answer
     * @returns {Object}
     * @private
     */
    private makeFormula;
    /**
     * Returns formula in equation presentation
     * @example 5 + ? = 6
     * @param {String[]} formula
     * @param {Number} answer
     * @returns {IFormula}
     * @private
     */
    private makeEquation;
}