dprod(x,y) returns the product x*y.
FORTRAN 77 and later
result = dprod(x, y)
x - The type shall be real.y - The type shall be real.The return value is of type real(8).
program test_dprod
real :: x = 5.2
real :: y = 2.3
real(8) :: d
d = dprod(x,y)
print *, d
end program test_dprod