eq { diff { hop { filter_eq { all_rows ; school ; jackson } ; join date } ; hop { filter_eq { all_rows ; school ; lake } ; join date } } ; -23 years } = true
select the rows whose school record fuzzily matches to jackson . take the join date record of this row . select the rows whose school record fuzzily matches to lake . take the join date record of this row . the second record is 23 years larger than the first record .