User:Isomorphyc/Sandbox/grc-rows-ipa/head arguments with unmarked ambiguous vowels

70.07% of head= arguments are ambiguous unless one assumes breves; I could make a few more assumptions, especially about diphthongs, to lower this substantially, but I don't think they would be correct 100% of the time. There are probably still a few errors here: as the comment in grc-pronunciation says, Greek vowels are hard.