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SubalgebraRepr

representation of a polynomial as a subalgebra element

Syntax
SubalgebraRepr(F: RINGELEM, L: LIST): RECORD
SubalgebraRepr(R: RING, F: RINGELEM, L: LIST): RECORD

Description
This function returns the representation of a polynomial as a subalgebra element in terms of the subalgebra generators.

Example
/**/  Use QQ[s,t];
/**/  L := [s^3, s^2*t, s*t^2, t^3];
/**/  indent(SubalgebraRepr(s^6*t^6, L));
record[
  IsInImage := true,
  OnePreImage := x[1]^2*x[4]^2,
  ker := ideal(x[3]^2 -x[2]*x[4], x[2]*x[3] -x[1]*x[4], x[2]^2 -x[1]*x[3])
]
/**/  SubalgebraRepr(s^6*t^6, L).IsInImage;  -- for obsolete "IsInSubalgebra"

See Also