How do European patents judge whether a patent is a divisional application of another patent?

The simplest way to judge: when you search for European patents, you will see that the description of the patent specification (the first page of the public text) has the priority to write this patent, the division of cases and so on.

In the intermediate law, the content of the divisional application should be made public in the parent case, so it can also be distinguished from the content.

The most stupid way: you do a search, and there will be the same patent of this patent on the website of the European Patent Office, so you can find it one by one. O(∩_∩)O