primelt.spad line 101 [edit on github]
FunctionsSpacePrimitiveElement provides functions to compute primitive elements in functions spaces.
primitiveElement(a1, a2)
returns [a, q1, q2, q]
such that k(a1, a2) = k(a)
,
, and ai
= qi
(a)q(a) = 0
. The minimal polynomial for a2
may involve a1
, but the minimal polynomial for a1
may not involve a2
; This operations uses resultant.
primitiveElement([a1, ..., an])
returns [a, [q1, ..., qn], q]
such that then k(a1, ..., an) = k(a)
,
, and ai
= qi
(a)q(a) = 0
. This operation uses the technique of Groebner basis.