isSubface -- Checks whether a face is a subface of another face.

• Usage:

  isSubface(F,G)

• Inputs:
  • F, a face,
  • G, a face,
• Outputs:
  • a Boolean value,

i1 : R=QQ[x_0..x_4];

i2 : C=simplex R;

i3 : G=C.fc_3_0

o3 = x x x x
      0 1 2 3

o3 : face with 4 vertices

i4 : F=C.fc_2_0

o4 = x x x
      0 1 2

o4 : face with 3 vertices

i5 : H=C.fc_3_3

o5 = x x x x
      0 2 3 4

o5 : face with 4 vertices

i6 : isSubface(F,G)

o6 = true

i7 : isSubface(F,H)

o7 = false