isCI -- whether the ring is complete intersection

• Usage:

  isCI R or isCI I

• Inputs:
  • R, a quotient ring, of a polynomial algebra by an ideal contained in the irrelevant maximal ideal
• Outputs:
  • a Boolean value, whether the local ring obtained by localizing R at the irrelevant maximal ideal is complete intersection

i1 : Q = QQ[x,y,z];

i2 : isCI (Q/ideal(x^2,x*y,y*z,z^2))

o2 = false

i3 : isCI (Q/ideal(x^2,y^2))

o3 = true