compress(Arrangement) -- extract nonzero equations

• Function: compress

• Usage:

  compress A

• Inputs:
  • A, a hyperplane arrangement,
• Outputs:
  • a hyperplane arrangement, a loopless arrangement

i1 : R = QQ[x,y,z]

o1 = R

o1 : PolynomialRing

i2 : A = dual arrangement {x,y,x-y,z} -- the last element of this arrangement is 0

o2 = {-x , x , x , 0}
        1   1   1

o2 : Hyperplane Arrangement 

i3 : compress A

o3 = {-x , x , x }
        1   1   1

o3 : Hyperplane Arrangement