-- -*- M2-comint -*- {* hash: 220354978 *}

i1 : A =  QQ[x_1,x_2,a_1,a_2]

o1 = A

o1 : PolynomialRing

i2 : cc = {ideal A => 1} -- the characteristic ideal of R = CC[x_1,x_2] 

o2 = {ideal () => 1}

o2 : List

i3 : cc1 = BMM(cc,x_1)   -- cc of R_{x_1}

o3 = {ideal () => 1, ideal(x ) => 1}
                            1

o3 : List

i4 : cc12 = BMM(cc1,x_2) -- cc of R_{x_1x_2}

o4 = {ideal () => 1, ideal(x ) => 1, ideal(x ) => 1, ideal (x , x ) => 1}
                            2               1                2   1

o4 : List

i5 :