Use the menu
Document / Comparison/Merge / New
Comparison... (Ctrl+N)
The
New Text File Comparison,
New Binary File Comparison and
New Image Comparison menu items open an empty view
in which you can select data to compare in many ways.
See
Manage a
comparison/merge view for an explanation about selecting
data to compare.
The
New Comparison... command opens a dialog box. It
allows you to compare text, binary files or images.
Once the box is open, select the right panel "Two-way
Comparison" or "Three-way comparison".
Unselect the Merge checkbox to open as a simple
comparison, or select it and choose (optionnally) where to
write the merge result.