On the Functional Unity of Phonological Rules

V~.p/VC[_ _]CV-long V_.pI{VC [_V]cv}-long The structural sameness in this example is limited entirely to the fact that in both rules vowels are deleted; this deletion does not occur in similar environments, and, furthermore, only short vowels are deleted in (5), but both long and short vowels are deleted in (4). It is not, of course, sufficient that rules be structurally similar for collapsing to be In the standard theory of generative phonology (as represented, for example, by Chomsky and Halle, 1968), the principal requirement which determines whether or not two or more phonological rules may be partially collapsed is that the rules share overt structural propertiea.! For example, rule (I) and (2) below may be collapsed by means of the brace notation into (3) by virtue of the fact that the rules contain a largely identical environment and the same class of segments undergoes the same structural change in both cases: (1) .p~V IC-O#-(2) .p~V IO-CC (3) .p~V/O-C{~ The above example is one where the structural similarity of the rules is striking. But the brace notational convention will also collapse rules such as (4) and (5) as well: 1 I would like to thank Morris Halle both for suggesting that I undertake the detailed examination of Yawelmani which led to thiJ paper, and for suggesting to me certain elements of the analysis of Yawelmani .which I have edcpted. I wo~ld abo like.to thank a number of people for reading this paper and/or discuaing