private void BtnProcessarSoR_Click(object sender, RoutedEventArgs e)
        {
            if (IsSelecionadoSOR())
            {
                Set conjuntoA = GetConjuntoByID(comboBox1S.SelectedValue.ToString());
                Set conjuntoB = GetConjuntoByID(comboBox2S.SelectedValue.ToString());
                Set conjuntoC = GetConjuntoByID(comboBox3S.SelectedValue.ToString());


                List <ElementWithValue> elementsA = new List <ElementWithValue>();

                foreach (Element ele in conjuntoA.ListElements)
                {
                    elementsA.Add(new ElementWithValue(ele));
                }

                List <ElementWithValue> elementsB = new List <ElementWithValue>();

                foreach (Element ele in conjuntoB.ListElements)
                {
                    elementsB.Add(new ElementWithValue(ele));
                }

                List <ElementWithValue> elementsC = new List <ElementWithValue>();

                foreach (Element ele in conjuntoC.ListElements)
                {
                    elementsC.Add(new ElementWithValue(ele));
                }

                Relationship relationAB = new Relationship
                {
                    Domain   = elementsA,
                    Codomain = elementsB
                };

                SetPair ab             = new SetPair();
                string  firstOperation = comboBox1O.SelectedValue.ToString();

                switch (firstOperation)
                {
                case "<":
                    ab = relationAB.LessThan();
                    break;

                case ">":
                    ab = relationAB.GreaterThan();
                    break;

                case "=":
                    ab = relationAB.EqualsValues();
                    break;

                case "x²":
                    ab = relationAB.EqualsValues();
                    break;

                case "²√":
                    ab = relationAB.EqualsValues();
                    break;
                }

                Relationship relationBC = new Relationship
                {
                    Domain   = elementsB,
                    Codomain = elementsC
                };

                SetPair bc = new SetPair();
                string  secondOperation = comboBox2O.SelectedValue.ToString();

                switch (secondOperation)
                {
                case "<":
                    bc = relationBC.LessThan();
                    break;

                case ">":
                    bc = relationBC.GreaterThan();
                    break;

                case "=":
                    bc = relationBC.EqualsValues();
                    break;

                case "x²":
                    bc = relationBC.EqualsValues();
                    break;

                case "²√":
                    bc = relationBC.EqualsValues();
                    break;
                }

                relationAB.Name = $"{conjuntoA.Name} X {conjuntoB.Name} X {conjuntoC.Name}";
                SetPair result = relationAB.ComposedRelationship(ab, bc);

                Classification classification = new Classification(result, elementsA, elementsC);
                txtSaida.Text = $"{relationAB.Name} = {result.ListPairToString()} \n" +
                                $"{classification.AllClassifications()}";
            }
        }