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(0:2)pt(0)=3*ex_R4Ppt(1)=1*ex_R4Ppt(2)=2*ex_R4Pprint"(L1)",is_collinear_R4P(pt(0),pt1=pt(1),pt2=pt(2))endprogram volatile_doctest