$ emacs filepath
- lines operations
% save file
$ C+x, C+s
% copy
$ M+w
% cut
$ C+w
% paste
$ C+y
% quit emacs
$ C+x, C+c
- Program running
% Execute one function of ocaml
$ C+c, C+e
% Execute the whole file
$ C+c, C+b
% Give the type of the term under the cursor
$ C+c, C+t