DEF FN  fib(x) = FIB(x)

'============================
FUNCTION  FIB(int n) TYPE int
'============================

    IF n < 2 THEN
        PRINT n

    ELSE
        n1 = 0
        n2 = 1
        FOR i = 1 TO n
            sum = n1 + n2
            n1 = n2
            n2 = sum
        NEXT
        PRINT n1
    END IF
END FUNCTION

'--- less than 2
FIB(0)
FIB(1)

'--- greater than or equal to 2
FIB(2)
FIB(3)
FIB(4)
FIB(5)
FIB(6)
FIB(7)
FIB(8)
FIB(9)

'--- using an alias
'fib(9)