user: Question: What is the nationality of the ship with a tonnage larger than 5507 sunk by an U-584?
Columns: ['Date', 'Name', 'Nationality', 'Casualties', 'Tonnage', 'Sunk by…']
Types: ['text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['29 April 1943', 'McKeesport', 'United States', '1', 6198.0, 'U-258']
SQL:

assistant: SELECT "Nationality" FROM "Table" WHERE "Tonnage" > 5507.0 AND "Sunk by…" = 'U-584';