Though this entry is notated with the symbol for an unspecified vowel, ⟨V⟩, in this case it does not mean the vowel is indeterminate. Rather, both *bi- and *ba- existed in opposition and became conflated to various degrees in the descendants, such that it is most parsimonious to unify them under one headword. The same is the case for *lV-.
fossiziled perhaps Akkadian: 𒅅(bašûm, “to be or become”), and 𒁉𒊑(biri), 𒁀𒊑(bari) as opposed to Proto-West Semitic*bayna where *bV- fused instead with the preposition found as Akkadian 𒀀𒈾(ana), 𒄿𒈾(ina), as well as in 𒁀𒇻(balu), 𒁀𒆷(bala), 𒁀𒀠(bal, “without”)