and { only { filter_eq { all_rows ; elevation msl ; 3400 msl } } ; eq { hop { filter_eq { all_rows ; elevation msl ; 3400 msl } ; city district } ; santiago } } = true
select the rows whose elevation msl record fuzzily matches to 3400 msl . there is only one such row in the table . the city district record of this unqiue row is santiago .