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

TMS,
Awesome, tried it and it works!

BUT as I said earlier duplicates for me are both:
London Amsterdam vs Amsterdam London AND London Amsterdam vs London Amsterdam

Your formula seems to work only with the first case (London Amsterdam vs Amsterdam London) while ignoring the second case.

Could you advise me how could I have a function that accounts for both cases at once?

And thank you once again for the first formula

@TMS,@Crooza

Guys, now it works like a charm. Really appreciate the support, thank you!