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BB.MultMat

Computes the i-th multiplication matrix associated to a border basis.
Syntax
          
BB.MultMat(I:INT, OO:LIST, BB:LIST):MAT

          

Description
Computes the I-th multiplication matrix associated to the given input OO-border basis BB of the ideal generated by the polynomials of BB where I is an index number in the range 1..NumIndets(). The output is a matrix.

Example
Use QQ[x,y];

BB.MultMat(1,
           [1, y, y^2, y^3, x, xy, x^2, x^2y],
           [xy^2, x^3 + xy, y^4, xy^3, x^2y^2, x^3y]);

-------------------------------
Mat([
  [0, 0, 0, 0, 0, 0, 0, 0],
  [0, 0, 0, 0, 0, 0, 0, 0],
  [0, 0, 0, 0, 0, 0, 0, 0],
  [0, 0, 0, 0, 0, 0, 0, 0],
  [1, 0, 0, 0, 0, 0, 0, 0],
  [0, 1, 0, 0, 0, 0, -1, 0],
  [0, 0, 0, 0, 1, 0, 0, 0],
  [0, 0, 0, 0, 0, 1, 0, 0]
])
-------------------------------


See Also