e.g., [[2, 5], [4, 5], [-3, 4]] or 2 5; 4 5; -3 4; or [[2*x^3-3, x^2],[-x, 3*x+1]] or 2*x^3-3 x^2; -x 3*x+1; (no spaces within the polynomials)
Default value is \(-1\) means the algorithm will be applied to all columns.
The default value is \(-1\) means each leading coefficient will be used to reduce elements in all rows above it.