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
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program volatile_doctestuse vecfor_R16Ptype(vector_R16P)::pt(0:3)pt(0)=-1*ey_R16Ppt(1)=1*ex_R16Ppt(2)=1*ey_R16Ppt(3)=-1*ex_R16Pprint"(L1)",is_concyclic_R16P(pt(0),pt1=pt(1),pt2=pt(2),pt3=pt(3))endprogram volatile_doctest