subroutine a()
import, none
implicit none
end subroutine a


subroutine b()
import, all
implicit none
end subroutine b


subroutine c()
import :: a, b
implicit none
end subroutine c


subroutine d()
import :: a, b
implicit none
end subroutine d


subroutine e()
import, only: a, b
implicit none
end subroutine e


subroutine f()
import :: a, b
import :: c
import :: d, e, f
implicit none
end subroutine f
