Given that we're in a vim story, I'll reply with a little vim tip…
Vim has digraph support built-in¹, so for your example the first few digraphs are In, p*, >=, h*. It is also how I typed the ellipsis on the first line of this comment(,.), and the superscript footnotes(1S and 2S).
A more complete Unicode solution for vim is available in Christian Brabandt's excellent plugin².