// The simple surface singularity An and all non-free // indecomposable MCM modules LIB "conn.lib"; int n = 100; ring s = 0, (x,y,z), dp; ideal i = xz+y^(n+1); qring a = std(i); list MCM,sMCM; int l; for (l=1;l<=n;l++) { matrix M[2][2] = x,-y^(n+1-l),y^l,z; MCM[l] = M; matrix sM[2][2] = z,y^(n+1-l),-y^l,x; sMCM[l] = sM; } print("Surface An:"); print("-------"); int i; for(i=1;i<=size(MCM);i++) { print("Module:"); print("-------"); print(MCM[i]); print("-------"); print("Obstructions:"); print("-------"); print(KSKernel(MCM[i])); print(LClass(MCM[i])); print("-------"); }