The idea is to write a verb which gives the Kronecker product.
https://en.wikipedia.org/wiki/Kronecker_product
For example:
]a=:2 2$2 3 5 7
2 3
5 7
]b=:1+4=i.3 3
1 1 1
1 2 1
1 1 1
a kr b
2 2 2 3 3 3
2 4 2 3 6 3
2 2 2 3 3 3
5 5 5 7 7 7
5 10 5 7 14 7
5 5 5 7 7 7
Note each entry in a times b appears as a block in the Kronecker product.
This may have been discussed in this forum before, but let's try to
rethink the problem.
The first time I was challenged with this question was in June of 1999
at a "J in the Math classroom" workshop at Messiah College. My (possibly
faulty) recollection was that their were four established Jers there
(Ken Iverson, Richard Brown, Donald McIntyre?? and myself). We
investigated defining kr. We each had a laptop, sitting in the 4 chairs
in the picture:
http://webbox.lafayette.edu/~reiterc/j/ke_iverson/wdsc00017.jpg
It was revolutionary for the era that we were computing, but we were not
in a laboratory.
Happy Jing,
Cliff
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