Answer:
CROSS JOIN (/^\s*symmetric\s*difference\s*$/)
Explanation:
Remember, in SQL (Structured Query Language) operations, we can use the CROSS JOIN function to take data from one row of a table in the database and join it with each row of another table.
In other words, the result of FULL OUTER JOIN minus the INNER JOIN of the data set would require a CROSS JOIN operation which would the two different rows into one row.