No, I have it the right way around. Artificial languages can be irregular, so your order doesn’t follow.
No regular language can be natural, though, so if you come across a regular language, you can always correctly conclude that it’s artificial through modus tollens:
“If a language is natural, then it is not regular. This language is regular, therefore it is not natural.”
Minor nitpick, you have causality inverted. Esperanto is artificial and therefore regular.
No, I have it the right way around. Artificial languages can be irregular, so your order doesn’t follow.
No regular language can be natural, though, so if you come across a regular language, you can always correctly conclude that it’s artificial through modus tollens:
“If a language is natural, then it is not regular. This language is regular, therefore it is not natural.”