Complicated IF function

Hi guys, it's me again!

I have a little complication, here how it goes:

I have 1000+ train routes. Previously, with the help of a certain forum member we were able to determine the starting point and end point of each route.

Now I need to check for duplicates in a following way (please see the screenshot):
IF cell B2 EQUALS any cell in column B (besides it's own obviously) OR any cell in column C (again, besides it's own) AND cell C EQUALS any cell in column B (besides it's own obviously) OR any cell in column C (again, besides it's own); if true - then "Yes"; if false - then "No"

As you can see, I know what I want to achieve but I simply don't know the right combo

Really hope someone will be kind enough to help

I attached a spreadsheet as well for your convenience

All the best,
Nick