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. > A variable in mathematics is quite different > than that in computer programming languages. The word variable originated in mathematics, and is used differently in imperative languages but with the same as the mathematical meaning in (purely or mostly purely) functional languages. It's just that the notion of varying is different in math and the latter kind of languages, compared to what one can be used to in imperative programming. 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 /. 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. 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. >> 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. ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
