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_R8P type(vector_R8P) :: pt pt = 4 * ex_R8P + 3 * ey_R8P print "(L1)", pt == 5_I8P endprogram volatile_doctest