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_doctestuse vecfor_R16Ptype(vector_R16P)::ptpt=ex_R16P+ey_R16Pcall pt%normalizeprint"(3(F4.2,1X))",abs(pt%x),abs(pt%y),abs(pt%z)endprogram volatile_doctest