ecart.syz

a ecart.syz b
array a; array b;
b : [syzygy gb tmat input];  gb = tmat * input 
Example 1: [ [( (x Dx)^2 + (y Dy)^2 -1) (  x y Dx Dy -1)] (x,y) 
             [ [ (Dx) 1 (Dy) 1] [(x) -1 (y) -1 (Dx) 1 (Dy) 1]] ] ecart.syz /ff set 
 ff 0 get ff 3 get mul pmat 
 ff 2 get  ff 3 get mul [ff 1 get ] transpose sub pmat ; 
  
To set the current ring to the ring in which ff belongs 
      ff getRing ring_def  
Example 2: [[ [(x^2) (y+x)] [(x+y) (y^3)] [(2 x^2+x y) (y+x+x y^3)]] (x,y) 
             [ [(Dx) 1 (Dy) 1] [ (x) -1 (y) -1] ]  [[0 1] [-3 1] ] ] ecart.syz pmat ; 
  
cf. ecart.gb
    /ecart.autoHomogenize 0 def



Nobuki Takayama 2020-11-24