%% gbdiff.sm1 [ (x,y) ring_of_differential_operators [[(Dx) 1 (Dy) 1]] weight_vector 0 ] define_ring [ (x Dx + y Dy). (Dx^2 + Dy^2). ] /ff set ff { [[(h). (1).]] replace homogenize} map /ff2 set [ff2] groebner dehomogenize ::

Nobuki Takayama 2020-11-24