and { only { filter_eq { all_rows ; surface ; clay } } ; and { eq { hop { filter_eq { all_rows ; surface ; clay } ; year } ; 1994 } ; eq { hop { filter_eq { all_rows ; surface ; clay } ; championship } ; rome } } } = true
select the rows whose surface record fuzzily matches to clay . there is only one such row in the table . the year record of this unqiue row is 1994 . the championship record of this unqiue row is rome .