and { only { filter_eq { filter_eq { all_rows ; location ; china } ; authors ; yuan } } ; eq { hop { filter_eq { filter_eq { all_rows ; location ; china } ; authors ; yuan } ; name } ; didactylornis } } = true
select the rows whose location record fuzzily matches to china . among these rows , select the rows whose authors record fuzzily matches to yuan . there is only one such row in the table . the name record of this unqiue row is didactylornis .