Re: Question about mfpetersson

On Mon, Mar 17, 2025 at 11:38:22AM +0000, Ahmad Mostafa Ismail El-Guindy wrote:
> Hello,
> 
> I am not sure what exactly am I doing wrong, but I am getting unexpected behavior from mfpetersson which seems to violate linearity. Since <Delta, E_{12}>=0 shouldn't the first line below give <Delta, Delta>? Why is it returning 0 instead?
> 
> (12:22) gp > mfpetersson(mfsymbol(mfDelta), mfsymbol(mflinear([mfDelta,mfEk(12)],[1,2])))
> %43 = 0
> (12:25) gp > mfpetersson(mfsymbol(mfDelta), mfsymbol(mflinear([mfDelta,mfEk(12)],[1,0])))
> %44 = 1.0353620568043209223478168122251645932 E-6 + 0.E-44*I
> (12:25) gp > mfpetersson(mfsymbol(mfDelta), mfsymbol(mflinear([mfDelta,mfEk(12)],[0,1])))
> %45 = 0

Karim has fixed this bug in the master branch.

Now

? mfpetersson(mfsymbol(mfDelta), mfsymbol(mflinear([mfDelta,mfEk(12)],[1,2])))
%1 = 1.0353620568043209223478168122251645992E-6-1.4909815660416053635E-42*I
? mfpetersson(mfsymbol(mfDelta), mfsymbol(mflinear([mfDelta,mfEk(12)],[1,0])))
%2 = 1.0353620568043209223478168122251645932E-6+0.E-44*I
? mfpetersson(mfsymbol(mfDelta), mfsymbol(mflinear([mfDelta,mfEk(12)],[0,1])))
%3 = 1.1364530545674266445E-42-5.829401611591239015E-43*I

Thanks for reporting it!
Bill