How do I type a double overline (over 2 characters like oo or oi)?
How do I type a double overline (over 2 characters like oo or oi)? I know how to get it over a single character like ō or ĕ, but I need a single line extending over 2 adjacent characters to indicate that they're pronounced as a diphthong.
iMac, OS X Mavericks (10.9.4)