I could argue that replacing "x" and "y" with "[" and "]" removes the trappings of Mathematical notation and is therefore a barrier to Mathematics teaching.
> From: Don Watson > > I agree that this can be done, but it isn't implicit and it adds > trappings of Computer Science that are a barrier to Mathematics > teaching. > > Don > > > > sqrsum =: 4 : '%:x + y' > > 3 sqrsum 5 > > 2.82843 > > 3 + 5 > > %: 8 > > %: 8 > > 2.82843 > > > > > > 2009/4/30 Don Watson <[email protected]> > > > >> Hi Don, > >> > >> You said: > >> > >> > Maybe I'm really missing something, but why use "[" and "]" at > >> > all? > >> > Just use "x" and "y". > >> > >> That's an interesting question. If I have the J expression: > >> > >> %:x + y > >> > >> and want to make a verb sqrsum, I could define a way of doing it > - > >> that > >> doesn't presently exist exactly in this form - such that: > >> > >> sqrsum =: %:x + y > >> > >> or that: > >> > >> sqrsum =: %: [ + ] > >> > >> and that in either case: > >> > >> 3 sqrsum 5 is equivalent to: %: 3 + 5 > >> > >> In the second case > >> > >> 1) I have a form that is full of nothing but verbs. > >> 2) I can state that the arguments are defined implicity. > >> > >> In the first case I need a convention that x and y are special > >> nouns used in named verbs with a special purpose. I obviously have > >> nouns > >> as > >> well in this verb definition, and I think it is harder to suggest > >> that argument inclusion is implicit. > >> > >> Don ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
