Dear Roberto, Yes, normalisation methods in GiNaC undergone some modification over that period as well. Thus particular form of the expression can be different now. Best wishes, Vladimir -- Vladimir V. Kisil http://www.maths.leeds.ac.uk/~kisilv/ Book: Geometry of Mobius Maps https://doi.org/10.1142/p835 Soft: Geometry of cycles http://moebinv.sourceforge.net/ Jupyter notebooks: https://github.com/vvkisil/MoebInv-notebooks

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On Fri, 14 May 2021 22:36:13 +0200, Roberto Bagnara <bagnara@cs.unipr.it> said:

RB> On 5/14/21 3:33 PM, Vladimir V. Kisil wrote: >>>>>>> On Fri, 14 May 2021 15:08:09 +0200, Roberto Bagnara >>>>>>> <bagnara@cs.unipr.it> said: RB> On 5/14/21 9:52 AM, Vladimir V. Kisil wrote: >> >> Dear Roberto! It seems that Ginsh and parser in GiNaC are >> >> implemented differently. Ginsh understands postfix factorial >> >> notation like "3!" but GiNaC parser is not. GiNaC parser is >> >> still happy with "factorial(3)". Best wishes, Vladimir >> >> RB> Thanks Vladimir! But please help me understand: I did not RB> change anything in the part of the code invoking the GiNaC RB> parser, and I did not change the tests. So the situation you RB> are describing, i.e., GiNaC parser not understanding postfix RB> factorial notation, is something that changed from, say, 10 RB> years ago. In other words, do you agree that, say, 10 years RB> ago, the GiNaC parser was accepting that notation? >> It seems that before 2008-08-21 GiNaC and Ginsh had used the same >> parser, which Ginsh is using till now. After a patch they >> diverged in this respect. So it is quite well possible that your >> code was running with the old version of GiNaC but cannot do this >> now without some alteration. RB> Dear Vladimir, RB> This explains everything. Now I am investigating failures in RB> the regression test-suite. One of the most promising examples RB> for my diagnosis efforts is this: RB> simplification for output of RB> -1+1/12*sqrt(sqrt(3)*sqrt(12))*sqrt(12)+1/12*sqrt(-sqrt(3)*sqrt(12))*sqrt(12) RB> was expected to be -1+(1/2+1/2*I)*sqrt(2) but resulted in RB> -1+(1/2+1/2*I)*4^(1/4) RB> From what you write I gather that back in 2008, or even before, RB> we obtained sqrt(2) where we now obtain 4^(1/4). RB> Thanks, RB> Roberto RB> -- Prof. Roberto Bagnara Applied Formal Methods Laboratory RB> Department of Mathematical, Physical and Computer Sciences RB> University of Parma, Italy http://www.cs.unipr.it/~bagnara/ RB> mailto:bagnara@cs.unipr.it