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)::pt(1:2)pt(1)=ex_R16P+ey_R16P+ez_R16Ppt(2)=ex_R16P+ey_R16P-ez_R16Pprint"(L1)",pt(1)/=pt(2)endprogram volatile_doctest