6 select( # We keep only records with errors
7 .root and # We need .root
9 $m[.root].root != null or # A root should have no root itself
10 .parent != .root and # We need .parent different .root
11 $m[.parent].root != .root # The parent's root should the same root.
14 ) | select(length > 0) # we keep only records with errors
15 ) | select(length > 0) # we keep only records with errors