Translate the following question to SQL: What are the names of customers who have not taken a Mortage loan?

Schema: CREATE TABLE bank (
    branch_ID INT   PRIMARY KEY,
    bname varchar(20),
    no_of_customers INT,
    city varchar(10),
    state varchar(20),
    UNIQUE (branch_ID)
);

CREATE TABLE customer (
    cust_ID varchar(3)   PRIMARY KEY,
    cust_name varchar(20),
    acc_type char(1),
    acc_bal INT,
    no_of_loans INT,
    credit_score INT,
    branch_ID INT,
    state varchar(20),
    UNIQUE (cust_ID),
    FOREIGN KEY (branch_ID) REFERENCES bank(branch_ID)
);

CREATE TABLE loan (
    loan_ID varchar(3)   PRIMARY KEY,
    loan_type varchar(15),
    cust_ID varchar(3),
    branch_ID varchar(3),
    amount INT,
    UNIQUE (loan_ID),
    FOREIGN KEY (cust_ID) REFERENCES customer(Cust_ID),
    FOREIGN KEY (branch_ID) REFERENCES bank(branch_ID)
);
user
SELECT cust_name FROM customer EXCEPT SELECT T1.cust_name FROM customer AS T1 JOIN loan AS T2 ON T1.cust_id  =  T2.cust_id WHERE T2.loan_type  =  'Mortgages'
assistant