private void editValue_Click(object sender, System.EventArgs e)
        {
            var termViewItem          = listView1.SelectedItems[0];
            var term                  = _terms[termViewItem.Index];
            var editVariableValueForm = new EditVariableValueForm(term);

            editVariableValueForm.OnSaveVariableValue += (name, a, b, c, d) =>
            {
                var trapFunc = term.AccessoryFunc as TrapFunc;
                if (trapFunc == null)
                {
                    return(false);
                }

                if (trapFunc.A != a || trapFunc.B != b || trapFunc.C != c || trapFunc.D != d)
                {
                    term.AccessoryFunc = new TrapFunc(a, b, c, d);
                }
                return(true);
            };

            editVariableValueForm.ShowDialog();

            RefreshFormListView();
        }
        private void addValue_Click(object sender, System.EventArgs e)
        {
            var addVariableValueForm = new EditVariableValueForm();

            addVariableValueForm.OnSaveVariableValue += (name, a, b, c, d) =>
            {
                if (_terms.Any(x => x.Name == name))
                {
                    return(false);
                }
                _terms.Add(new Term(name, a, b, c, d));
                return(true);
            };
            addVariableValueForm.ShowDialog();

            RefreshFormListView();
        }