Parenthesization bug
Richard B. Kreckel
kreckel at thep.physik.uni-mainz.de
Fri Jan 25 14:52:36 CET 2002
Hi,
On Fri, 25 Jan 2002, Roberto Bagnara wrote:
> there is a bug somewhere in GiNaC whereby some non-redundant parentheses
> are not output. The problem is shown below by means of simple `ginsh'
> session, but it can be reproduced equally well with C++ code.
>
> $ ginsh
> ginsh - GiNaC Interactive Shell (GiNaC V1.0.4)
> __, _______ Copyright (C) 1999-2002 Johannes Gutenberg University Mainz,
> (__) * | Germany. This is free software with ABSOLUTELY NO WARRANTY.
> ._) i N a C | You are welcome to redistribute it under certain conditions.
> <-------------' For details type `warranty;'.
>
> Type ?? for a list of help topics.
> > 2*I^(1/3);
> 2*I^(1/3)
> > (2*I)^(1/3);
> 2*I^(1/3)
> > 2*(I^(1/3));
> 2*I^(1/3)
> >
>
> If this is confirmed to be a bug, we would need to develop a fix or
> a workaround quite urgently.
Indeed, it's a bug. Internally, these are differnt objects. It just
seems to be their output, i.e. power::print(). Look at this:
> (2*I)^(1/3);
2*I^(1/3)
> print(%);
power, hash=0xbffff638, flags=0x3, nops=2
2i (numeric), hash=0x80000840, flags=0xf
1/3 (numeric), hash=0x80000020, flags=0xf
Can you look into that method?
Regards
-richy.
--
Richard B. Kreckel
<Richard.Kreckel at Uni-Mainz.DE>
<http://wwwthep.physik.uni-mainz.de/~kreckel/>
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