Nodes of different colours represent the following:
Solid arrows point from a submodule to the (sub)module which it is descended from. Dashed arrows point from a module or program unit to modules which it uses.
program volatile_doctest use vecfor_RPP type(vector) :: pt pt = 4 * ex + 3 * ey print "(L1)", 5._R16P == pt endprogram volatile_doctest