/**
 * Validates if a CPF (Cadastro de Pessoas Físicas) is valid.
 *
 * @param {string} cpf - The CPF value to be validated.
 * @returns {boolean} True if the CPF is valid, false otherwise.
 *
 * @example
 * ```typescript
 * isValidCpf("123.456.789-09"); // true
 * isValidCpf("12345678909"); // true
 * isValidCpf("00000000000"); // false (reserved number)
 * isValidCpf("12345678900"); // false (invalid checksum)
 * ```
 */
export declare const isValidCpf: (cpf: string) => boolean;