PROGRAM vector                    ! illustrate use of arrays
DIM a(3),b(3)                     ! arrays defined in DIM statement
CALL initial(a(),b())
CALL dot(a(),b())
CALL cross(a(),b())
END

SUB initial(a(),b())
    LET a(1) = 2
    LET a(2) = -3
    LET a(3) = -4
    LET b(1) = 6
    LET b(2) = 5
    LET b(3) = 1
END SUB

SUB dot(a(),b())
    LET dot_product = 0
    FOR i = 1 to 3
        LET dot_product = dot_product + a(i)*b(i)
    NEXT i
    PRINT "scalar product = "; dot_product
END SUB

SUB cross(r(),s())
    ! arrays can be defined in main program or subroutine
    ! note use of dummy variables
    DIM cross_product(3)
    FOR component = 1 to 3
        LET i = mod(component,3) + 1
        LET j = mod(i,3) + 1
        LET cross_product(component) = r(i)*s(j) - s(i)*r(j)
    NEXT component
    PRINT
    PRINT "three components of the vector product:"
    PRINT " x "," y "," z "
    FOR component = 1 to 3
        PRINT cross_product(component),
    NEXT component
END SUB