RE: [Axiom-developer] Complex exponentiation and 0

[Page, Bill]

On Tuesday, June 22, 2004 6:11 AM Martin Rubey
address@hidden wrote:
> ...
> Shouldn't this mean that 0^0 is undefined in EXPR INT,
> for example: x^y ?  Hmm, I see: in x^y we do not have a
> problem since there is no zero...

I don't understand. 0::EXPR INT and 1::EXPR INT exist.

 (0::EXPR INT) ^ (0::EXPR INT) = (1::EXPR INT)

> ...
> So, in other words, there is no bug,

There is a bug.

  0::CARD ^ 0::CARD

should be 1::CARD

> except that in
> 
> Vanuxem Grégory writes:
> > In complex(Float) and Complex(SingleFloat), we have to change the
> > exponentiation so that
> >         complex(0,0)^complex(0,0.0)
> > or
> >         complex(0,0)^complex(2,2.0)
> > doesn't use log.
> 
> the *latter* really should give 0?
>

No. complex(0,0)^complex(0,0.0) is like 0^0.0 and should
return

  '0**complex(0,0.0)' is undefined

The message 'log 0 generated' is confusing but technically
correct.
 
Regards,
Bill Page.