Prolog Combine Rule
i need to write a rule which consists of sub rule. 

Any idea how to achieve this ? 

    isloanaccept(Name, LoanAmount, LoanTenure) 
    :- 	customer(Name, bank(_),customertype(_),
    	citizen(malaysian),age(Age),credit(C),
    	income(I),property(car|house)), 
    	Age >= 18,
    	C > 500, 
        I > (LoanAmount / LoanTenure) / 12.
    lowerinterest(Senior) :- isseniorcitizen(Senior).

For instance, i need to check the customer type .
If customer type is VIP, interest lower. 
If age is above 60, interest lower. 

Please help. 

Thanks. 
Prolog Combine Rule
===

i need to write a rule which consists of sub rule. 

Any idea how to achieve this ? 

    isloanaccept(Name, LoanAmount, LoanTenure) 
    :- 	customer(Name, bank(_),customertype(_),
    	citizen(malaysian),age(Age),credit(C),
    	income(I),property(car|house)), 
    	Age >= 18,
    	C > 500, 
        I > (LoanAmount / LoanTenure) / 12.
    lowerinterest(Senior) :- isseniorcitizen(Senior).

For instance, i need to check the customer type .
If customer type is VIP, interest lower. 
If age is above 60, interest lower. 

Please help. 

Thanks. 