On 2009.02.01 18:20:04, you,
 the extraordinary John Randall, emitted:

> Does anyone have a good example of a dyadic fork?  By this I mean one
> of the form fgh where f and g both use x and y, there are no [ or ],
> no constant functions, and no @ or @: .  I am having trouble coming up
> with nontrivial examples.

It occurs to me that an exercise that sometimes comes
up in logic texts goes cutely into a J fork:

Assume the only boolean function is nand (*:)
Express and (*.)

   dand=: (*: *: *:)"0
   0 1 dand/ 0 1
0 0
0 1
   0 1 dand/ 0 1 dand/ 0 1
0 0
0 0

0 0
0 1
   (0 1 dand/ 0 1) dand/ 0 1
0 0
0 0

0 0
0 1

I wouldn't go so far as to claim nontriviality :-)

N.
-- 
Nollaig MacKenzie
http://www.amhuinnsuidhe.net
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