Entanglement question

I have a previously entangled bell pair, the type does not matter for this situation, one half of that pair is in Tokyo (Bob) and the other is in London (Alice). I need a method for checking to see if Bob is entangled or not with the following caveats: The method i use cannot break any entanglement that may or may not still exist I do not care about the values relating to any properties of the entangled particle/qubit I do not have access to any classical methods of communicating with Alice so I cannot check anything in London or anywhere else that is not local to me I do have access to any scientific equipment currently existing The method needs to be able to be performed more than once Thanks in advance submitted by /u/Designer_Idea5498 [link] [comments]