I am a simple user, you are not only the architect, but also the implementor. Most of all I consider J as a mathematical tool, that's the way I use it anyhow, and in mathematics I would immediately define u&.(w`v) as I did. What's more, I would extend &, &: en &:. accordingly. Just to have a complete and (IMO) elegant language.
But, as a Dutch poet once wrote (and google translated): "but between dream and deed, laws stand in the way, and practical objections." After all, there is a workaround. R.E. Boss -----Original Message----- From: Programming <[email protected]> On Behalf Of Henry Rich Sent: woensdag 17 november 2021 16:35 To: [email protected] Subject: Re: [Jprogramming] x u&.(w`v) y 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 > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm -- This email has been checked for viruses by AVG. https://www.avg.com ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
