On 11 April 2011 17:45, Raul Miller <[email protected]> wrote: > I am not sure if this mean that, for example, the definition of + > would need to conclusively define the following concepts: > > o numbers > o arrays > o rank
That would be an extremely perverted characterization of all I said. If this is some kind of a joke, then consider me lacking the type of sense of humour that would have allowed me to appreciate it. > http://www.jsoftware.com/help/dictionary/d300.htm uses -/ in a way > that can only be valid for right-left computation. Ah, great! So, to see a meaningful, non-trivial example of what / does, one has to read about determinants? Would it not be simpler to define / properly, and in addition, give an example of, say, alternating sum (-/3 5 8 2 === 3-5-8-2 === 4) -- both in the /'s own article? > I do not think this is possible without including some rigorous > constraints on the background of the reader (and the result would > necessarily be scattered around for people lacking that background). Consider replacing the vague first sentence of http://www.jsoftware.com/help/dictionary/d420.htm with For y = y1...yn and n>1, u/y is equivalent to y1 u y2 u ... u yn. If 1=#y, the result of u/y is y. This describes what / currently does (except the 0=#y case). Where are the `rigorous constraints on the background of the reader' that you mentioned? > Unless 0=#y (which is explicitly treated), u/y necessarily has _1+#y > instances of u. This follows immediately from the first sentence at > http://www.jsoftware.com/help/dictionary/d420.htm In my understanding, it doesn't follow. Apparently we have differing notions of logical deducibility. ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
