face -- Generate a face.

Synopsis

• Usage:

  face(L)

  face(S)

  face(L,C)

  face(L,C,d,j)

• Inputs:
  • L, a list,
  • S, a set,
  • C, an embedded complex,
  • d, an integer, bigger or equal to -1
  • j, an integer, non-negative
• Outputs:
  • a face,

Description

i1 : R=QQ[x_0..x_4]

o1 = R

o1 : PolynomialRing

i2 : I=ideal(x_0*x_1,x_1*x_2,x_2*x_3,x_3*x_4,x_4*x_0)

o2 = ideal (x x , x x , x x , x x , x x )
             0 1   1 2   2 3   3 4   0 4

o2 : Ideal of R

i3 : C=idealToComplex I

o3 = 1: x x  x x  x x  x x  x x  
         0 2  0 3  1 3  1 4  2 4

o3 : complex of dim 1 embedded in dim 4 (printing facets)
     equidimensional, simplicial, F-vector {1, 5, 5, 0, 0, 0}, Euler = -1

i4 : F=C.fc_1_0

o4 = x x
      0 2

o4 : face with 2 vertices

i5 : F==face(vert F,C,1,0)

o5 = true

See also

• Face -- The class of all faces of complexes or co-complexes.
• Complex -- The class of all embedded complexes.
• CoComplex -- The class of all embedded co-complexes.