-- -*- M2-comint -*- {* hash: 1359411603 *}

i1 : R = QQ[a,b,c];

i2 : I = ideal"a2-b2,abc"

             2    2
o2 = ideal (a  - b , a*b*c)

o2 : Ideal of R

i3 : M = I/(I^2+a*I)

o3 = subquotient (| a2-b2 abc |, | a4-2a2b2+b4 a3bc-ab3c a2b2c2 a3-ab2 a2bc |)

                               1
o3 : R-module, subquotient of R

i4 : presentation M

o4 = {2} | a b2 0 0  |
     {3} | 0 0  a b2 |

             2       4
o4 : Matrix R  <--- R

i5 :