[Jprogramming] x u&.(w`v) y

[Henry Rich]

Here's an argument against:

The dual [x] u&.v y says 'apply u, but with a different point of view.  
First transform [x and] y, then apply u, then transform the result back 
to the original point of view.'

The semidual x u&(a:`v) y says 'u&.v, but the point-of-view business 
applies only to y'.  x goes through unchanged.

What you propose puts x and y in different spaces to begin with; 
presumably w and v transform them to a common point of view, but then 
the result is transformed back by  applying BOTH inverses.  I don't see 
an application for this, or an easy verbal description of it.

Henry Rich

On 11/17/2021 10:18 AM, R.E. Boss wrote:
>     *&.(>:`<:)/ i.2 3
> |domain error
> |   *    &.(>:`<:)/i.2 3
>
>     *&.(a:`<:)/ i.2 3
> 1 4 9
>     *&.(a:`<:)&.(>:`a:)/ i.2 3
> 2 6 12
>
> so why not define
> x u&.(w`v) y
>   as
> x u&.(w`a:)&.(a:`v) y
> ?
>
>
> R.E. Boss
>
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