thats not how this works. you are the one making a claim, its on you to provide supporting proof.

Depends on your definition or concept. Is this an attempt by a conservative to nudge us toward Trump?
Asking to prove an opinion on a definition is just silly!

If we agree that the color we see as lettuce is called green and adopt that convention, it could be said that it is a fact that lettuce is green, aside from red varieties, but if you choose to call green red and yell alternative facts or fake news, I don't have time for you.

A fact is a truth. A fact exists whether or not humans see/contemplate it. A "fact" is a simple noun which represents a truth. "Concept" might have very different meanings, depending on whose mind is shaping it.

"Concepts" are a human concept... unless aliens have concepts, too.

And speaking of aliens, I would expect that, as a mark of intelligence, facts—like mathematics—would be discovered independent from us.

But who knows? For now, we only know that facts are localized to human minds.

Define 'human concept', please.