callling_func_intent.f90

program calling_func
implicit none

   real :: x, y, z, disc

   x= 1.0
   y = 5.0
   z = 2.0

   call intent_example(x, y, z, disc)

   Print *, "O valor do discriminante vale"
   Print *, disc

end program calling_func


subroutine intent_example (a, b, c, d)     
implicit none     

   ! dummy arguments      
   real, intent (in) :: a     
   real, intent (in) :: b      
   real, intent (in) :: c    
   real, intent (out) :: d   

   d = b * b - 4.0 * a * c 

end subroutine intent_example