Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_56 ( round_2 VARCHAR, round_4 VARCHAR, round_3 VARCHAR )

### Question ###
What is Round 2 when Round 4 is Double and Round 3 is Single?

### Accurate SQL ###

SELECT round_2 FROM table_name_56 WHERE round_4 = "double" AND round_3 = "single"