Darren Duncan writes:
> At 8:27 PM -0400 4/12/05, John Macdonald wrote:
> >The mathematical definition of xor for two arguments is "true if
> >exactly one argument is true, false otherwise".
>
> Yes.
>
> >When that gets
> >generalized to multiple arguments it means "true if an odd number
> >of the arguments are true, false otherwise".
>
> Is this the official mathematics position?
Naively, yes. And mathematics othen revels in the naive position (any
other would not be consistent):
xor(1, 0, 0, 1, 1, 0)
1 xor 0 xor 0 xor 1 xor 1 xor 0
1 xor (0 xor (0 xor (1 xor (1 xor 0))))
1 # parity 1, odd number of arguments true
> If not, I would generalize it like this: true If >= 1 arg is true
> and >= 1 arg is false, otherwise false.
>
> Is that better or worse?
I don't think that's what xor is testing. I can't quite think of why
you'd need that (but I can't quite think of why you'd need xor
either...).
Luke
