I would not call it "ablaut" (which I reserve for the Indo-European
e/o/zero forms, e.g. Smyth $ 36), because it really is compensatory
lengthening due to liquid + sigma (Symth $ 37). Thus (exx. from Sihler):
pres. *meno: > MENW; aor. *emensa > EMEINA
pres. *krinyo: > KRI:NW; aor. *ekrinsa > EKRI:NA
pres. *phanyo: > FAINW; aor. *ephansa > EFHNA
pres. *stelyo: > STELLW; aor. *estelsa > ESTEILA
pres. *phtheryo: > FQEIRW; aor. *ephthersa > EFQEIRA
>As I've (briefly) browsed the liquids, I see that -E- forms are certainly
>the most frequent such formulations, but that are others which, by using
>ablaut in my explanation, I don't have to explain separately:
>
>GAMEW > EGHMA (though it also has a first aor. form, EGAMHSA)
>KERDAINW > EKERDANA (also with a first aorist EKERDHSA)
>KAQAIRW > EKAQARA
>BASKAINW > EBASKANA
>EUFRAINW > HUFRANA (and quite a few other -AINW verbs)
These all show compensatory lengthening as well, since the -ANA forms include
a long A, -A:NA. (The -AI- diphthong occurred the original *-any- palatized,
then depalatized.)
Stephen Carlson
-- Stephen C. Carlson : Poetry speaks of aspirations, scarlson@mindspring.com : and songs chant the words. http://www.mindspring.com/~scarlson/ : -- Shujing 2.35