[...] the most familiar English example of a rule which causes difficulties of the sort which are at issue here is Trysillabic Shortening (or Trisyllabic Laxing). This rule shortens a vowel if followed by at least two more vowels, of which the first is unstressed: (4) V → [-long]/_CoViCOVj where Vi is not metrically strong [...]. - Kiparsky (2004), a pag.127-128