the K3 carpet of type b1,b2 is the correspondence scroll of type b1,b2 with respect to the ideal Delta2, where Delta ⊂P1 x P1 is the ideal of the diagonal.
i1 : betti res carpet{1,3} 0 1 2 3 o1 = total: 1 5 5 1 0: 1 . . . 1: . 3 2 . 2: . 2 3 . 3: . . . 1 o1 : BettiTally |