> ***I also pointed out that /i a u/ is more phonologically likely than /e
> Obviously, I did not express my thought unambiguously.
> I certainly will grant that height contrast is fundamental.
> My point was rather, if the pre-PIE front vowel was [i] or [e] (two
> front vowels of different heights), what difference would it make
> for reconstruction purposes? My answer is: none that I can see; but
> Miguel has not yet commented, and pre-PIE *i, *a, and *u is his
> reconstruction proposal. I have proposed pre-PIE *e, *a, and *o.