[From string (line 9) ]                                                                
                                                                                       
@startuml                                                                              
!$start=4                                                                              
!$end=$start+5                                                                         
                                                                                       
                                                                                       
!function $highlight($from,$to)                                                        
  db@$from <-> @$to : setup time                                                       
  db@$from -> addr@$to : hold                                                          
!endfunction                                                                           
^^^^^                                                                                  
 This function does not have any !return directive. Declare it as a procedure instead ?