solveApp = new SolveApprox(this);
// Conti Andrea - undo
undoManager = new GraphUndoManager();
undoProxy = new UndoManagerProxy(undoManager);
editUndo = new ActionUndo(this, undoManager);
editRedo = new ActionRedo(this, undoManager);
// end
// Bertoli Marco
pauseSimulation = new PauseSimulation(this);
stopSimulation = new StopSimulation(this);
exit = new Exit(this);