compare or merge 2 or 3 files?

 

 

Use the menu Document /  Comparison/Merge / New Comparison... (Ctrl+N) 

 

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.

See also