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ker

Kernel of a K-algebra homomorphism

Syntax
Ker(M:TAGGED("$alghom.Map")):IDEAL

Description
This function returns the kernel of a K-algebra homomorphism.

Example
  Use QQ[s,t];
  L := [s^3, s^2t, st^2, t^3];
  SAM := SubalgebraMap(L);  --***OBSOLETE MANUAL: WORK IN PROGRESS***
  SAM;
Record[
  DomainIndets := SubalgebraRing::[x[1], x[2], x[3], x[4]],
  Images := CurrentRingEnv::[s^3, s^2t, st^2, t^3],
  ElimIdeal := AlgHomRing :: Ideal(
  -y[1]^3 + x[1],
  -y[1]^2y[2] + x[2],
  -y[1]y[2]^2 + x[3],
  -y[2]^3 + x[4])
]
-------------------------------
  Ker(SAM);
SubalgebraRing :: Ideal(x[3]^2 - x[2]x[4], x[2]x[3] - x[1]x[4], x[2]^2 - x[1]x[3])
-------------------------------

See Also