Re: Recursive and Pure Primes
- --- In firstname.lastname@example.org,
"David Broadhurst" <d.broadhurst@...> wrote:
> On Planet Zog the sloths are bipeds, all having the sameClearly each sloth has at least 11 toes,
> number of toes, distributed between their two feet,
> with each foot having at least one toe. All possible
> sub-species occur. Each sloth has a composite number
> of toes on one foot, but not on the other.
since no smaller number will do.
Kermit sent me, off-line, the germ of the
proof that each sloth has *precisely* 11 toes.
Here is my own proof.
Let N be the number of toes of each sloth.
1) N is odd, else a sub-species of
sloth would have N/2 toes on each foot,
which is impossible, since no number
may be both composite and non-composite.
2) We know that N - 2 is composite,
since 2 is prime. Hence N > 9.
3) Since N > 9, we require that
N - 4, N - 6, N - 8 are all prime.
But one those 3 numbers must be divisible by 3.
The only prime divisible by 3 is 3.
Hence N - 8 = 3.
So N = 11 and we are done.
Comment: My anti-theological bias derives from
"Which two mighty powers have, as I was going to tell you,
been engaged in a most obstinate war for six-and-thirty
moons past. It began upon the following occasion. It is
allowed on all hands, that the primitive way of breaking
eggs, before we eat them, was upon the larger end; but his
present majesty's grandfather, while he was a boy, going to
eat an egg, and breaking it according to the ancient
practice, happened to cut one of his fingers. Whereupon the
emperor his father published an edict, commanding all his
subjects, upon great penalties, to break the smaller end of
their eggs. The people so highly resented this law, that
our histories tell us, there have been six rebellions raised
on that account; wherein one emperor lost his life, and
another his crown. These civil commotions were constantly
fomented by the monarchs of Blefuscu; and when they were
quelled, the exiles always fled for refuge to that empire.
It is computed that eleven thousand persons have at several
times suffered death, rather than submit to break their eggs
at the smaller end. Many hundred large volumes have been
published upon this controversy: but the books of the
Big-endians have been long forbidden, and the whole party
rendered incapable by law of holding employments."
Fortunately, debate on the non-primality of units
has not, so far as I am aware, led to any fatality.
David (per proxy J. Swift)