Yep this is the exact issue. This problem comes up frequently in a first discrete math or formal mathematics course in universities, as an example of how subtle mistakes can arise in induction.

I haven’t used the XPS 13 personally but my experience and all my friends’ experience with the XPS lineup is that despite their build quality, they’re quite prone to failure. On my 15, the keyboard failed multiple times, as well as one of the fans and eventually one thunderbolt port, all within a span of 4 years.

They’re beautiful machines that really should be quality, but in practice for some reason they haven’t lasted for me. On the plus side though, Dell does at least offer service manuals, and lots of parts can be replaced by a user (on the 15 you can easily replace fans, RAM, SSDs, and with some work you can replace the top deck, display, and SD reader).

He’s apparently said he was born in 1988. In another thread others mentioned that would make him 21 when he started his PhD, which checks out.

Not that unusual IMO, lots of people start their PhD directly after completing their Bachelor’s. If they weren’t born born in the first half of the year then they’ll have completed their BS by 21 and start the PhD either at 21 or 22.