complexToIdeal -- Compute the Stanley-Reisner ideal.

i1 : K=QQ;

i2 : R=K[x_0..x_4];

i3 : I=ideal(x_0*x_1,x_1*x_2,x_2*x_3,x_3*x_4,x_4*x_0);

o3 : Ideal of R

i4 : D=idealToComplex I

o4 = {x  x  , x  x  , x  x  , x  x  , x  x  }
       2  4    0  3    0  2    1  3    1  4

o4 : complex with 5 facets on the vertices x  x  x  x  x  
                                            0  1  2  3  4

i5 : complexToIdeal(D)

o5 = ideal (x x , x x , x x , x x , x x )
             3 4   0 4   2 3   1 2   0 1

o5 : Ideal of R