eq { diff { hop { filter_eq { all_rows ; name / designation ; saturn machine pistol } ; year of intro } ; hop { filter_eq { all_rows ; name / designation ; serlea } ; year of intro } } ; -5 years } = true
select the rows whose name  designation record fuzzily matches to saturn machine pistol . take the year of intro record of this row . select the rows whose name  designation record fuzzily matches to serlea . take the year of intro record of this row . the second record is 5 years larger than the first record .