| ring r=0,(x,y,z),dp;
ideal I=xz,yz,x3-y3;
def L=hres(I,0);
print(betti(L),"betti");
→ 0 1 2
→ ------------------------
→ 0: 1 - -
→ 1: - 2 1
→ 2: - 1 1
→ ------------------------
→ total: 1 3 2
L[2]; // the first syzygy module of r/I
→ _[1]=-x*gen(1)+y*gen(2)
→ _[2]=-x2*gen(2)+y2*gen(1)+z*gen(3)
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