4 or 64, neither is a good description of how it works outside of protein building. Same as saying that C++ is a 100-word language because it's the size of the ASCII alphabet: correct but not helpful
That's only correct in the same sense that it's "correct" to say DNA is a four-word language. It's not "correct in an unhelpful way", it's just incorrect.
I mean, neither really matter. TREE3 shows us that computational complexity explodes beyond all reason even in word limited simple systems with low connectivity.
Ah, I see your idea, but codons aren't DNA- they are a higher level construct (only used in the context of transcribed and translated genes that code for proteins).
Also, several of those codons aren't mapped to amino acides (stop codons) and the codons are re-used to code for the same amino acids, so it's really redundant compared to that.
DNA codes for a lot more than just genes... you're just conflating several unrelated concepts. For example, regulatory regions don't care about codons at all.
If you're just saying "genes are defined in units of codons", no complaint. And the biophysics of synonymous codons are highly complex; in most cases, you can substitute them in and get the same exact protein function. There are lots of papers about corner cases in specific proteins, but it's still correct to say that synonymous codons code redundantly (this is a well-established fact of molecular biology).
It's not a 4-word language. It's a 64-word language. That's been known for about as long as we've known what DNA was.