I've checked Chapter 1 off, but that's only to say I've checked out the code and verified it gives the results claimed. I didn't see it as my job to rewrite the treatment to make it clearer – which I can't do anyway without being sure what the author is trying to convey.
I must confess that first section completely baffles me. I cannot see how to relate the "general rule" to actual examples of J code, although the article goes on to do just that … it seems. Does the "rule" represent real working J code? – even in a generic sense? Is it even true? (Theorems have to be true, but rules only have to be obeyed.) If it isn't always true, am I to understand it as a rule-of-thumb?And if it is in fact universally true, what procedure must I, the novice reader, follow in order to convert the "generics" into "specifics" to verify the fact? I'd be grateful for someone to cast light on the matter. Failing which, maybe I ought to remove my green checkmark, stand aside to let someone else scratch their head over it. On Sat, Jun 16, 2018 at 12:41 AM, David Lambert <b49p23t...@gmail.com> wrote: > 50 Shades of j chapter 1 now says that rule is completely general. I'm > somewhat weak on j transformations and proofs, although what was there was > incorrect because of a counterexample: > > > every=.&> NB. uses compose > each=.&.> NB. uses under > rule =: (f every) -: >@(f each) > > NB. Is completely general? > > > thank you, Dave > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
