Left GB's
Quantum Algebra
Maximal Ideal
Gröbner Bases for Left and Two-Sided Ideals - (1)
ideal I2=e^2,f^2,h^2-1;
ideal L2=std(I2);
L2; // GB of left ideal
==> L2[1]=h2-1
L2[2]=fh-f
L2[3]=f2
L2[4]=eh+e
L2[5]=2ef-h2-h
L2[6]=e2
ideal T2=system("twostd",I2);
T2; // GB of two-sided ideal
==> T2[1]=h2-1
T2[2]=fh-f
T2[3]=f2
T2[4]=eh+e
T2[5]=2ef-h2-h
T2[6]=e2

This shows that I2 is a two-sided ideal itself.

Computations for I3

Sao Carlos, 08/02 http://www.singular.uni-kl.de