Nodes of different colours represent the following:
Solid arrows point from a file to a file which it depends on. A file is dependent upon another if the latter must be compiled before the former can be.
program volatile_doctest use vecfor_R4P type(vector_R4P) :: pt(1:2) pt(1) = ex_R4P pt(2) = ey_R4P print "(F3.1)", pt(1).dot.pt(2) endprogram volatile_doctest