[terminalbraid]

You can mathematically prove it is even by the accepted definitions of mathematics. If you disagree you disagree with prepositional logic.

[derdi]

I can, yes. Laypeople might not be able to, or be aware of the various (equivalent) accepted definitions.

And yes, this means that many laypeople are not effective at doing mathematics. Does this surprise you? If yes, then the linked article and Mastodon thread may be interesting to you. Which is why I submitted them.