"J"

Raul Deluth Miller rockwell@nova.umd.edu
Mon, 19 Dec 1994 08:27:29 -0500


   Thanks! (Pure ignorance on my part). Just out of interest, what is
   "J" and who owns it. Do they also own "j"?

Um...  It's not trademarked, so technically it's not owned.  However,
it is prior usage and would eventually cause no end of confusion
(especially on my part).  Finally, I think this issue is somewhat case
insensitive.

J is a programming language.

Really :-)

[It's an upgraded/enhanced/simplified version of APL.]

Um.. if you take a look at my .signature, you'll see a sample of what
j can look like.  This particular instance happens to be the RSA
encryption algorithm (except I've left out the actual mechanics of key
selection and limited myself to expressing the constraints of the
algorithm).

My primary constraint was the 4 line "good usage" limit on the length
of a signature.  Everything after NB. is a comment, but the last line
is completely executable without defining any external criteria.  [The
first line uses the word "public" which is really a meta-operation.
The second line uses the word "factors" which is intended to represent
an externally defined verb which provides the unique set of prime
factors of its argument, the third line has a fair bit of english
because it has some rather qualitative size constraints I couldn't
think of a better way to express.]

-- 
Raul D. Miller          N=:((*/pq)&|)@                 NB. public e, y, n=:*/pq
<rockwell@nova.umd.edu> P=:*N/@:#               NB. */-.,e e.&factors t=:*/<:pq
                        1=t|e*d    NB. (,-:<:)pq is four large primes, e medium
x-:d P,:y=:e P,:x                  NB. (d P,:y)-:D P*:N^:(i.#D)y [. D=:|.@#.d