Re: [Axiom-developer] Complex exponentiation and 0

[Martin Rubey]

This should have gone to axiom-devel also...

Martin Rubey writes:
 > David MENTRE writes:
 > 
 >  > Is your bug report related to:
 >  >   [bugs #9313] 0^0 handled inconsistently
 >  >   http://savannah.nongnu.org/bugs/?func=detailitem&item_id=9313
 >  > 
 >  > According to Martin comment, 0^0 is not mathematically defined.
 > 
 > Yes, it is related in some sense: if we adopt 0^0=1, the above should be
 > fixed. Otherwise, it could be left alone, although the error message will not
 > be entirely clear for everybody:
 > 
 > (9) -> (0.0**complex(0,0))
 >  
 >    >> Error detected within library code:
 >    log 0 generated
 > 
 > protected-symbol-warn called with (NIL)
 > 
 > Addendum to my previous post: it seems that within axiom 0^0 was assumed to 
 > be
 > undefined originally:
 > 
 > card.spad:                error "0**0 not defined for cardinal numbers."
 > float.spad:         y = 0 => error "0**0 is undefined"
 > float.spad:         r = 0 => error "0**0 is undefined"
 > float.spad:         n = 0 => error "0**0 is undefined"
 > interval.spad:    zero?(v) => if zero?(u) then error "0**0 is undefined" 
 > else 1
 > pscat.spad:            zero? r => error "0**0 undefined"
 > sf.spad:         zero? r => error "0**0 is undefined"
 > address@hidden algebra]$ grep -i "0 \*\* 0" *
 > combfunc.spad:          zero? second l => error "0 ** 0"
 > gaussian.spad:               zero? x => error "0 ** 0 is undefined"
 > gaussian.spad:               zero? x => error "0 ** 0 is undefined"
 > laurent.spad:        zero? x => error "0 ** 0 is undefined"
 > laurent.spad:          zero? x => error "0 ** 0 is undefined"
 > 
 > Martin