CREATE TABLE publication (publication_id NUMBER, book_id NUMBER, publisher CLOB, publication_date CLOB, price NUMBER)
CREATE TABLE book (book_id NUMBER, title CLOB, issues NUMBER, writer CLOB)

Show writers who have published a book with price more than 4000000.
SELECT T1.writer FROM book AS T1 JOIN publication AS T2 ON T1.book_id = T2.book_id WHERE T2.price > 4000000
SELECT "T1"."writer" FROM "book" "T1" JOIN "publication" "T2" ON "T1"."book_id" = "T2"."book_id" AND "T2"."price" > 4000000