~λ13;P17;JUFA
4.2	COPY, KILL AND DUAL.

4.2.1	"C"	Copy.

	This command copies the body or face from the  top of stack in a  reasonable
manner and  pushs it down. The copy of a body  includes all the parts of
that body. The copy of a face, creates a two-faced body lamina coincident
with the given face.

4.2.2	"K"	Kill.

	This command takes  the top body,  face,  edge or  vertex and
attempts to delete  it in a reasonable manner. Kill of a body deletes
it and all its parts. Kill of  a face removes the given face and  all
its edges and vertices but one  vertex, which is placed in the center
of  the given  face and  is returned  to the  stack. Kill of  an edge
removes the given  edge and its negative  face, NFACE(E).  Kill  of a
vertex removes the  vertex and all its edges and  faces but one face,
which is returned to the stack. The kill operation is not defined  in
cases which would  leave one-sided  faces or dangling  edges; however
the necessary trihedral  restrictions are not imposed so that certain
illegal kills are possible and other illegal kills are  fatal.

4.2.3 "αK" Edge-Vertex Kill.

	The "αK"  kill of an edge  removes the edge and  its negative
vertex,   NVT(E); the  positive vertex,   PVT(E), is repositioned to be at the
center of the original edge. The PVT(E) vertex is returned to the stack.



4.2.4	"βD"	Dual.
~W1,500;JUFA
	The "βD" command makes  the face/vertex dual of a  body; that
is all  the faces become vertices and  all the vertices become faces.
This command  will turn  dodecahedrons into  icosahedrons (or  jacks
into horny octahedrons) as illustrated.

~W1,1260;
H2;X0.70;
L270,-400;
*FIG424.PLT;FA