def saved_certificate_to_cnf(file_path):
    """ Load a certificate from file

        Parameters
        ----------
        file_path :string
            Path of the file that contains the certificate fo a cnf

        Returns
        -------
        set[(string,bool)]
            The object that represents the loaded certificate
        """
    cert = set()
    f = open(file_path, "r")
    for line in f:
        if line[0] == 'v' and line[2] != '0':
            for leterals in line.split(' ')[1:]:
                numeric_leterals =int(leterals)
                cert.add(('x{}'.format(abs(numeric_leterals)),True if numeric_leterals > 0 else False))
    return cert