On Thu, Apr 14, 2011 at 4:16 AM, Boyko Bantchev <[email protected]> wrote: > On 14 April 2011 04:23, Don Guinn <[email protected]> wrote: >> I was simply trying to point out that you chose to apply the meaning of >> "between" not from the J terminology of "between" but from some other >> context where it is not clear of order. J documentation makes it very clear >> for J context. > > Does it? How? I don't believe `between' is some notion specific > to J. I don't see a definition of it. Between is between, let's > not put a halo of specialness around it.
The only thing "special" about insert is that J evaluates the sentence that is obtained. Anyways, I take back my earlier comment about you asking J to be formal in the way other language references are formal -- when I went out to look at how c#, perl and javascript standards define join, I was not able to find any that gave special treatment to the case where the array length is 1. But I was using web searches, and perhaps I overlooked something? > On 14 April 2011 05:13, Raul Miller <[email protected]> wrote: >> That was exactly my point: People need to learn arithmetic before >> they can understand mathematical definitions of arithmetic. > > No, you maintained quite a different stand (to which I objected): > that in DoJ -- which for J is supposed to be the analogue of the > formal definition of arithmetic -- it is normal to have circular > definitions; that I should consider the definitions of \ and > determinant and who knows what else as part of the definition of /. My claim would have been that use of the definitions is inductive, and not circular. Specifically, I was saying that you need some exposure to all of a group of them before you could *master* any of that group. > The structure and content of a defining document have nothing to do > with `learning arithmetic'. There is /, and there are \, \., and > many others. If the examples accompanying the definitions of the > latter happen do use /, that's ok, but these examples are not > *the* definition of /, not even `parts of it', as you insist. They are, nevertheless, a part of the reference work I refer to as the dictionary of J. And, I see no reason to not consider them to provide relevant information. And, I see no reason why I should not use that information in building my mental model of what / means. > Or, to repeat what I've already said, > >> In all more or less formally presented systems (which, I assume, a >> programming language definition ought to be) these things work in the >> opposite direction: first establish a definition, then use it in further >> definitions and applications. And Godel has long since shown that only trivial axiomatic systems can be complete. Anyways, we are iterating on your statements here and perhaps I shall eventually acquire enough knowledge of what you are talking about to have some clue as to why you think these are important issues. >>> All I have been proposing is replacing the not sufficiently clear >>> definition of / with a clear one -- just what is expected from a >>> definition. >> >> But, of course, the dictionary's illustrations clear up that issue for >> people with enough background. > > I am forced to repeat myself again: > >>> Examples are not a substitute for definitions -- they are just an >>> illustrative aid. Why draw a distinction between "illustrative" and "clear"? Specifically, if you feel that the definition is "unclear" on one point, why do you feel that "illustration" is not a sufficient mechanism for making it "clear" on that point? -- Raul ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
