The system names are empty everywhere (the drop-down list at the top, row headers, checkbox/radiobox descriptions "Show" / "Show diff for ").
It would be enough to call it SystemA and SystemB if the real name is too long (but show the mapping to the real name at least once on the screen).
See e.g. http://quest.ms.mff.cuni.cz:7280/tasks/75-79/compare
The system names are empty everywhere (the drop-down list at the top, row headers, checkbox/radiobox descriptions "Show" / "Show diff for "). It would be enough to call it SystemA and SystemB if the real name is too long (but show the mapping to the real name at least once on the screen).