Vim: underscore(_) automatically converted to (<-)

Question

I have been writing R scripts in Vim for some time now. Starting an hour ago, I began facing an issue that every time I type an underscore (_), it gets automatically converted to <-.

What setting did I change for this to happen? Thanks!

Answer 1

:verbose imap _ should tell you which (probably filetype plugin) has set this.

It's less likely to be an abbreviation, but :verbose ia _ would tell you.