So I'm thinking about how "insofar" became a word. This slightly unfair comparison shows that it happened relatively recently.
Now, whenever I've seen it written, "insofar" is followed by "as". So I did some more digging.
This is terribly unscientific, I know. But it seems like the majority of uses of "insofar" are followed by "as". So here's the question:
Why did "insofar" become a word, and not "insofaras"?
Put differently (from a comment below): Long and regular association of these words in this order: "in so far" led to them being written as one word. Why didn't the same process produce "insofaras" given that almost all case of the former are cases of the latter?
A similar question could be asked of "inasmuch"…
I'm not looking for a historical explanation, rather a (possibly speculative) linguistic answer that explains why this happened as it did.