SQL Store selling all titles

Store selling all titles

INSERT stores (stor_id, stor_name, stor_address, city, state, zip)
VALUES ('9999', 'WE SUPPLY IT ALL', 'One Main St', 'Poulsbo',
    'WA', '98370')

-- By using a combination of hard-coded values and selecting every
-- title, generate a sales row for every title
INSERT sales (stor_id, title_id, ord_num, ord_date, qty, payterms)
SELECT '9999', title_id, 'PHONY1', GETDATE(), 10, 'Net 60'
FROM titles 

-- Find stores that supply every title
SELECT ST.stor_id, ST.stor_name, ST.city, ST.state
FROM stores ST
-- WHERE NOT EXISTS
--     (SELECT * FROM titles T1
--     WHERE NOT EXISTS
--         (SELECT * 
--         FROM titles T2 JOIN sales S ON (T2.title_id=S.title_id)
--         WHERE T2.title_id=T1.title_id AND ST.stor_id=S.stor_id)
--     )

WHERE NOT EXISTS
    (SELECT * FROM titles T1
    WHERE NOT EXISTS
        (SELECT * 
        FROM sales S
        WHERE S.title_id=T1.title_id AND ST.stor_id=S.stor_id)
    )