Quoting Trans <transfire / gmail.com>:

> As I pointed out, there really isn't an ambiguity.

Well, when we're speaking of grammars, "ambiguity" refers to
situations where the formal grammar (by itself) permits more than
one possible interpretation of the same text.

As you point out, in cases like that you can introduce additional
criteria -- extrinsic to the formal grammar -- so they aren't
"real" ambiguities, but it's far better to avoid ambiguous grammars
in the first place.  Unambiguous grammars are much easier to work
with.

> BUT that doesn't mean it's neccessarily nice for the human.

Yeah, that's the other thing.  As I think Terrence pointed out once,
ambiguities correlate strongly to user confusion.

-mental