The syntax using the | character is now obsolete.                 
          Please use the <<procedure>> stereotype instead.                  
          For more details, visit https://plantuml.com/activity-diagram-beta
                                                                            
          The syntax using the ] character is now obsolete.                 
          Please use the <<task>> stereotype instead.                       
          For more details, visit https://plantuml.com/activity-diagram-beta
                                                                            
                                                                            
                                                                            
                                                                            
                                                                            
                                                                            
                                                                            
                                                                            
                                                                            
                                                                            
                                                                            
                                                                            
                                                                            
                     Listen user                                            
                                                                            
                                                                            
                                                                            
                                                                            
                                   Prepare                                  
                                   answer                                   
                                                                            
                                                                            
                                                                            
                                                                            
                     Reply user                                             
                                                                            
                                                                            
                                                                            
                                                                            
                                    forever