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function validCPF(cpf) {
    cpf = cpf.replace(/[^\d]+/g,'');

    if(cpf == '') return false;

    if (cpf.length != 11 ||
        cpf == "00000000000" ||
        cpf == "11111111111" ||
        cpf == "22222222222" ||
        cpf == "33333333333" ||
        cpf == "44444444444" ||
        cpf == "55555555555" ||
        cpf == "66666666666" ||
        cpf == "77777777777" ||
        cpf == "88888888888" ||
        cpf == "99999999999")
        return false;

    var add = 0;

    for (i=0; i < 9; i ++)
        add += parseInt(cpf.charAt(i)) * (10 - i);
    var rev = 11 - (add % 11);
    if (rev == 10 || rev == 11)
        rev = 0;
    if (rev != parseInt(cpf.charAt(9)))
        return false;

    add = 0;

    for (var i = 0; i < 10; i ++)
        add += parseInt(cpf.charAt(i)) * (11 - i);

    rev = 11 - (add % 11);

    if (rev == 10 || rev == 11)
        rev = 0;

    if (rev != parseInt(cpf.charAt(10)))
        return false;

    return true;
}

// CPF validation
Validation.add('validate-cpf', 'Informe um CPF válido!', function(v) {
    return validCPF(v);
});