up previous next
IsInSubalgebra

check if one polynomial is in a subalgebra

Syntax
SubalgebraRepr(F: RINGELEM, L: LIST): RINGELEM
SubalgebraRepr(F: RINGELEM, M:TAGGED("$alghom.Map")): RINGELEM

Description
***** NOT YET IMPLEMENTED *****

This function tests whether a polynomial is in a subalgebra, i.e. can be written as a polynomial expression of the elements of a list.

Example
  Use QQ[s,t];
  L := [s^3, s^2t, st^2, t^3];
  IsInSubalgebra(s^6t^6, L);
True
-------------------------------
  SAM := SubalgebraMap(L);
  IsInSubalgebra(s^6t^6, SAM);  -- more efficient for repeated checks
True
-------------------------------

See Also