I remember the “curly less than” (or equal) as a notation for partial ordering, like that of the complex numbers or vectors. But such an ordering cannot be used for grading, as grading needs a complete ordering. And since grading uses the lexicographical and type ordering (as you showed in your last example), we could easily define comparison on characters and boxes by
< ←→ ≼ for characters < ←→ ≼&> for boxes It wouldn’t even hurt existing programs. R.E. Boss p.s. I would have preferred all primitives to have infinity rank anyhow, but that is another discussion > -----Oorspronkelijk bericht----- > Van: Programming <programming-boun...@forums.jsoftware.com> > Namens Roger Hui > Verzonden: zaterdag 2 maart 2019 04:47 > Aan: programm...@jsoftware.com > Onderwerp: Re: [Jprogramming] Comparing comparisons > > For the ordering used in sorting, what you want is the symbol denoted by ≺ > "curly less than" U+227A or ≼ "curly less than equal" U+227C in conventional > mathematical notation, with infinite dyadic ranks. It's not enough to make < > or <: work on characters because those functions have 0 dyadic rank. > > ≼ ←→ 0 1 -: /:@, > > f=: 0 1 -: /:@,&< > 'foo' f 'upon' > 1 > 'syzygy' f 'chthonic' > 0 > 'pi' f 3.14159 > 0 > > > > On Fri, Mar 1, 2019 at 5:10 PM Jimmy Gauvin > <jimmy.gau...@gmail.com<mailto:jimmy.gau...@gmail.com>> > wrote: > > > Hi, > > > > 'c' < 'b' doesn't work in APL either but 'c'='d' works in J and in APL. > > > > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
