Operations on FP-Algebras

This section describes operations on fp-algebras. Most of the operations are very similar to those for noncommutative free algebras; such operations are done by mapping the computation to the preimage ideal and then by mapping the result back into the fp-algebra. See the corresponding functions for the noncommutative free algebras for details.

A . i : AlgFP, RngIntElt -> AlgFPElt
Given an fp-algebra A, return the i-th indeterminate of A as an element of A.
CoefficientRing(A) : AlgFP -> Rng
Return the coefficient ring of the fp-algebra A.
Rank(A) : AlgFP -> RngIntElt
Return the rank of the fp-algebra A (the number of indeterminates of A).
DivisorIdeal(I) : AlgFP -> AlgFr
Given an ideal I of an fp-algebra A which is the quotient ring F/J, where F is a free algebra and J an ideal of F, return the ideal J.
PreimageIdeal(I) : AlgFP -> AlgFr
Given an ideal I of an fp-algebra A which is the quotient ring F/J, where F is a free algebra and J an ideal of F, return the ideal I' of F such that the image of I' under the natural epimorphism F -> A is I.
PreimageRing(A) : AlgFP -> AlgFr
Given an fp-algebra A which is the quotient ring F/J, where F is a free algebra and J an ideal of F, return the free algebra F.
OriginalRing(A) : AlgFP -> Rng
Return the generic free algebra F such that A is F/J for some ideal J of F.
IsCommutative(A) : AlgFP -> BoolElt
Return whether the algebra A is commutative.
I eq J : AlgFP, AlgFP -> BoolElt
Given two ideals I and J of the same fp-algebra A, return true if and only if I and J are equal.
I subset J : AlgFP, AlgFP -> BoolElt
Given two ideals I and J of the same fp-algebra A, return true if and only if I is contained in J.
I + J : AlgFP, AlgFP -> AlgFP
Given two ideals I and J of the same fp-algebra A, return the sum I + J.
I * J : AlgFP, AlgFP -> AlgFP
Given two ideals I and J of the same fp-algebra A, return the product I * J.
IsProper(I) : AlgFP -> BoolElt
Given an ideal I of the fp-algebra A, return whether I is proper; that is, whether I is strictly contained in A.
IsZero(I) : AlgFP -> BoolElt
Given an ideal I of the fp-algebra A, return whether I is the zero ideal. Note that this is equivalent to whether the preimage ideal of I is the divisor ideal of A.
V2.28, 13 July 2023