Abhinav Baid wrote:
>
> Thanks for the review. While working on this, I came across the
> following error:
>
> Function: ?*? : (UnivariatePolynomial(x,Fraction(Integer)),%) -> % is
> missing from domain: UnivariateLaurentSeries(Fraction(Integer),x,0)
> Internal Error
> The function * with signature $
> (UnivariatePolynomial x (Fraction (Integer)))$ is missing from
> domain
> UnivariateLaurentSeries(Fraction (Integer))x(0 . 1)
>
> I get this while multiplying li and ri (both of type LL) whose values are:
>
> li := x^-1*(xD) - x^-2
> ri := (xD) + 1
>
> Any reason for this? I think this is related to the previous warnings:
>
> not known that (LeftModule UP) is of mode (CATEGORY domain (SIGNATURE
> coerce ($ (Variable var))) (SIGNATURE differentiate ($ $ (Variable
> var))) (IF (has F (Algebra (Fraction (Integer)))) (SIGNATURE integrate
> ($ $ (Variable var))) noBranch))
AFAICS you need:
UTS ==> UnivariateTaylorSeries(F, var, cen)
US ==> UnivariateLaurentSeries(F, var, cen)
LL ==> LinearOrdinaryDifferentialOperator3(F, UTS, US)
LinearOrdinaryDifferentialOperator3 has declaration:
LinearOrdinaryDifferentialOperator3(Coeff : Ring,
A : AbelianMonoidRing(Coeff, NonNegativeInteger),
R : Join(DifferentialRing, LeftModule(A))
) ....
ATM you use UP as A. On UP we have assumption that it is
of UnivariatePolynomialCategory F, but this does not
imply that US is a LeftModule(UP). In fact, your declarations
allow
US := UnivariateLaurentSeries(F, x, 0)
UP := UnivariatePolynomial(y, F)
and clearly multiplying series in x by polynomial in y is fishy.
So FriCAS allows such multiplication only after you coerce
argumets to something for which meaning is clear.
ATM I do not know why FriCAS allowed you to compile your
original declarations, but using Taylor series instead of
polynomials should fix the problem.
It is possible that after such change you will need to
convert polynomials to Taylor series in a few more places.
--
Waldek Hebisch
[email protected]
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