/**
 * FormulaCleaner - Handles formula cleaning for Excel export
 *
 * This class fixes common issues with formulas when exporting to Excel:
 * 1. @ symbols incorrectly added by ExcelJS
 * 2. Double equals (==) issues
 * 3. Invalid formula syntax
 * 4. Special character handling
 */
export declare class FormulaCleaner {
    /**
     * Clean formula for Excel export
     * This is the main method that applies all cleaning rules
     */
    static cleanFormula(formula: string): string;
    /**
     * Remove @ symbols that ExcelJS incorrectly places
     */
    private static removeIncorrectAtSymbols;
    /**
     * Fix Excel function names and syntax
     */
    private static fixFunctionNames;
    /**
     * Validate and fix basic formula syntax
     */
    private static validateSyntax;
    /**
     * Handle special characters in formulas
     */
    private static handleSpecialCharacters;
    /**
     * Get summary of changes made during cleaning
     */
    private static getChanges;
    /**
     * Check if a formula is valid for Excel export
     */
    static isValidFormula(formula: string): boolean;
    /**
     * Special handling for array formulas
     */
    static cleanArrayFormula(formula: string, range?: string): string;
}