res-dual

[F V] res-dual G
G is the dual D-module of F. V is a list of variables.
Example 1:  [ [( x^3-y^2 )  ( 2 x Dx + 3 y Dy + 6 )  ( 2 y Dx + 3 x^2 Dy) ] 
              [(x) (y)]] res-dual 
Example 2:  [[1 3 4 5]] appell1 res-dual  
Example 3:  [ [(-x1 Dx1 + x1 + 2) (x2 Dx2 - Dx2 -3)] [(x1) (x2)]] res-dual 
Example 4:  [ [(x2 Dx2 - Dx2 + 4) (x1 Dx1 + x1 +3)] [(x1) (x2)]] res-dual 
            3 and 4 are res-dual each other. 
Example 5:  [ [[1 1 1][0 1 2]] [0 0]] gkz res-dual 
Example 6:  [ [[1 1 1][0 1 2]] [-2 -1]] gkz res-dual 
    
Example 7:  [ [(x Dx -1) (Dx^2)]     [(x)]] res-dual 
Example 8:  [ [[(1) (0)] [(0) (Dx)]] [(x)]] res-dual 
Example 9:  [ [((x Dx + x +1) (Dx-1))] [(x)]] res-dual



Nobuki Takayama 2020-11-24