eq { diff { hop { filter_eq { all_rows ; race ; flight stakes } ; date } ; hop { filter_eq { all_rows ; race ; cox plate } ; date } } ; -21 } = true
select the rows whose race record fuzzily matches to flight stakes . take the date record of this row . select the rows whose race record fuzzily matches to cox plate . take the date record of this row . the second record is 21 larger than the first record .