Assertion: mid vowel | /r/HasProperty | ladefoged
Facets:
Source sentences:
text: Tense vowels are sometimes claimed to be articulated with a more advanced tongue root than lax vowels, but this varies, and in some languages, it is the lax vowels that are more advanced, or a single language may be inconsistent between front and back or high and mid vowels (Ladefoged and Maddieson 1996, 302–4).