is a variable defined in `
Its value is
- This variable may be risky if used as a file-local variable.
The function used to split the main window between buffer-A and buffer-B.
You can set it to a horizontal split instead of the default vertical split
by setting this variable to `split-window-horizontally'.
You can also have your own function to do fancy splits.
This variable has no effect when buffer-A/B are shown in different frames.
In this case, Ediff will use those frames to display these buffers.
You can customize this variable.