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D.14.1.16 arrCone

Procedure from library arr.lib (see arr_lib).

Usage:
arrCone(A);
arrCone(A, ring_variable); arr A arrangement in variables x_1...x_n;

Return:
arr, the coned hyperplane Arrangement cA with respect to the given ring_variable, or the last ring_variable if none was given.

Note:
The hyperplanes are homogenized w.r.t. v and a new hyperplane H = ker(x_n+1) is added.

Example:
 
LIB "arr.lib";
ring R = 0,(x,y,z),dp;
arr  A = ideal(x+1, x,x-2,x-1);
arrCone(A, y);
==> _[1]=x+y
==> _[2]=x
==> _[3]=x-2y
==> _[4]=x-y
==> _[5]=y
==> 
arr B= ideal(x,y,x+y-1);
arrCone(B);
==> _[1]=x
==> _[2]=y
==> _[3]=x+y-z
==> _[4]=z
==> 
See also: arrCone; arrDecone; arrEssentialize; arrIsEssential; arrRestrict.