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_R4Ptype(vector_R4P)::pt(0:1)pt(1)=1*ex_R4P+2*ey_R4P+1*ez_R4Ppt(0)=2_I4P+pt(1)print"(3(F3.1,1X))",abs(pt(0)%x),abs(pt(0)%y),abs(pt(0)%z)endprogram volatile_doctest