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_R8Ptype(vector_R8P)::pt(0:2)pt(0)=3*ex_R8Ppt(1)=1*ex_R8Ppt(2)=2*ex_R8Pprint"(L1)",pt(0)%is_collinear(pt1=pt(1),pt2=pt(2))endprogram volatile_doctest