v

Set v of ZG-generators for the submodule '

(-1+x)e_a

(-1+y)e_b

(-xy+yx)e_c

(-1-x²-yx²-x²yx)e_b+(1+y)e_c

(-1+y+xy+x²y-yxy-xyxy-yx²y+yxyxy)e_a+(-x²-xyx-yx²-yxyx)e_b+(-x+y+x²y+yx²+xyx²-x²yx²y)e_c