[GiNaC-list] lsolve bug (and work around)

Alexei Sheplyakov varg at theor.jinr.ru
Sat Feb 16 11:50:26 CET 2008


Hello!

On Fri, Feb 15, 2008 at 03:53:48PM +0100, Diego Conti wrote:

> I think I have found a bug in lsolve. I have tested the following 
> program under ginac 1.3.9 and 1.4.1, and I obtain an incorrect result in 
> both cases: the linear system contains the equation lambda28=0, but I 
> obtain lambda28==lambda28 in the solution.

[snipped]
 
> I suspect the problem is the sqrt(3),

Yes, that's the problem. The coefficients are assumed to be either rational
expressions or numbers. And sqrt(3) is neither a rational expression nor
a number.

> since replacing it with an integer the result appears to be correct.

Replacing it with symbol("a") gives correct result too.

Best regards,
	Alexei

-- 
All science is either physics or stamp collecting.

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