Ralf Hemmecke <[email protected]> writes: > SparseUnivariateSkewPolynomial(R:Ring, sigma:Automorphism R, delta: R -> R): > UnivariateSkewPolynomialCategory R with > outputForm: (%, OutputForm) -> OutputForm > == SparseUnivariatePolynomial R add > > And the last line is the problem. It certainly implements multiplication > from the right, but, of course, in a commutative fashion.
Yes. > Multiplication from the right should rather expand the definition > > x * a == \sigma(a) * x + \delta(a) > > where x is the indeterminate of the skewpolynomial ring. > > So, I guess, adding > > (z: %) * (r: R): % == times(z, r*(1$%), sigma, delta) > > into the second chunk > > <<domain ORESUP SparseUnivariateSkewPolynomial>>= > > should solve Martin's problem and all the others that are just connected > to skew polynomials. I'm all for it. > BTW... it is *totally* ugly that this chunk > > <<domain ORESUP SparseUnivariateSkewPolynomial>> > > is split in two in such a way as it currently is. > I'd rather like to see something like > > <<domain ORESUP SparseUnivariateSkewPolynomial>>= > )abbrev domain ORESUP SparseUnivariateSkewPolynomial > ... > SparseUnivariateSkewPolynomial(R:Ring,sigma:Automorphism R,delta:R->R): > UnivariateSkewPolynomialCategory R with > ... > == SparseUnivariatePolynomial R add > <<domain ORESUP SparseUnivariateSkewPolynomial: add-body>> > @ > > > <<domain ORESUP SparseUnivariateSkewPolynomial: add-body>>= > import RepeatedSquaring(%) > _^(x:%, n:PositiveInteger):% == x ** n > ... > if R has Field then > leftDivide(a, b) == leftDivide(a, b, sigma) > rightDivide(a, b) == rightDivide(a, b, sigma) > @ > > Common initial white space should not be important in a chunk. Einverstanden! Martin --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/fricas-devel?hl=en -~----------~----~----~----~------~----~------~--~---
