Under the standard approach to UR discovery (Chomsky and Halle 1968; Kenstowicz and Kisseberth 1977), it is assumed that whenever possible, surface contrasts should be derived in a lawful way from underlying distinctions. In other words, if a surface contrast ([A] vs. [B]) can be distinguished using an underlying difference (/A/ vs. /B/), this is preferable to using some other technique, such a...