The contrastive hierarchy in phonology 2009 Dresher.pdf - CUNY ...

h. XII [u tense] [+tense]
The marking conventions are rather heterogeneous. Some take as their
inputs an unmarked feature value, [u F], whereas others have +/– values as their
input. These latter are statements of necessary universal implications, such as
that [+low] vowels are necessarily [–high] (VII), or that [+high] vowels are
necessarily [–low] (IX). Most rules converting u values to +/– values have
contexts specified only with +/– values, or variables ranging over these values
(VIII, X, XI), but some conventions also contain u/m values in their contexts
(only VI in the conventions shown, but the full set of markedness conventions
contains further examples).
Not all features are governed by markedness conventions in all contexts.
For example, convention X states that the unmarked value of [back] is + in the
context [+low] (low vowels are preferably back: /a/ is preferred to /æ/), but
there is no corresponding convention for [back] in the context [–low]. Therefore,
non-low vowels have no u/m value for [back], but only a +/– value.
No marking conventions convert a marked feature into +/– values. If for
some feature, F, a rule converts [u F] into [α F] in some context C, it follows
logically that a segment specified [m F] in the same context must receive the
opposite value, [–α F]. To make this explicit, Chomsky and Halle (1968: 403)
propose the interpretive convention in (5.3). Following Kean (1980) I will refer to
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