greater { hop { filter_eq { all_rows ; vessel ; lublin class } ; in service } ; hop { filter_eq { all_rows ; vessel ; deba class } ; in service } } = true
select the rows whose vessel record fuzzily matches to lublin class . take the in service record of this row . select the rows whose vessel record fuzzily matches to deba class . take the in service record of this row . the first record is greater than the second record .