COMMENT ⊗   VALID 00002 PAGES 
RECORD PAGE   DESCRIPTION
 00001 00001
 00002 00002	~H7
 00004 ENDMK
⊗;
~H7;
L0,-20,0*5,-61*5;
L0,20,0*5,61*5;
L-86*5,83*5,0*5,61*5,86*5,83*5;
L-86*5,-83*5,0*5,-61*5,86*5,-83*5;
H2;
L42*5,106*5,86*5,83*5,126*5,0*5,86*5,-83*5,42*5,-106*5,-42*5,-106*5;
L-42*5,-106*5,-86*5,-83*5,-126*5,0*5,-86*5,83*5,-42*5,106*5,42*5,106*5;

L-30,-10;FBedge~
L-380,-10;FBNFACE(edge)~
L240,-10;FBPFACE(edge)~

L-70,-370;FBNVT(edge)~
L-70,350;FBPVT(edge)~

L-360,320;FBNCCW(edge)~
L-390,-360;FBNCW(edge)~
L220,320;FBPCW(edge)~
L260,-360;FBPCCW(edge)~

I1600,0;
λ10;JC;FA[FIGURE 2.1 - Winged Edge Topology]
The orientation of links is as viewed from the exterior side of the surface.
The mnemonics in the figure, were derived as follows:

NFACE(edge)	Negative Face.
PFACE(edge)	Positive Face.
  PVT(edge)	Positive Vertex.
  NVT(edge)	Negative Vertex.

NCW(edge)	Next edge in Negative face Clockwise from Edge.
PCW(edge)	Next edge in Positive face Clockwise from Edge.
NCCW(edge)	Next edge in Negative face Counter Clockwise from Edge.
PCCW(edge)	Next edge in Positive face Counter Clockwise from Edge.