Bo Jacoby wrote:
> Can the expression
> u&(-v)*u&v
This is an interesting question in the general case, but I'll return to
that another time.
For your particular u and v the answer is yes:
2 (*];.0)@:(u&v)4
6 3 1 0 0
0 3 4 3 0
0 0 1 3 6
The trick is ];.0 which reverses all the axes of its input (basically
it's ($ $ |.@:,) ). This works in your case because that's the
relationship between u&v and u&(-v) : your u is a function table and
for your v the hook (-v) is just its reverse.
-Dan
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