text: #ifndef __MAINWINDOW_H
  #define __MAINWINDOW_H
  
  #include <QMainWindow>
  #include "Mathematics.h"
  #include "GraphicsBuilder.h"
  
  namespace Ui
  {
      class MainWindow;
  }
  
  class MainWindow : public QMainWindow
  {
      Q_OBJECT;
  
  public:
      explicit MainWindow(QWidget* parent = nullptr);
      ~MainWindow() override;
  
  public slots:
      void clickButtonCalculate();
  
  private:
      Ui::MainWindow* ui;
  };
  
  #endif // __MAINWINDOW_H
  