Thanks to all.  I got in trouble because I used a lousy example. 

    |.23
23
   23|.23
23

I thought  reverse  instead of  rotate . Instead  p  is just doing what it
is supposed to do.

   p=:-:|.
   p 'stresseddesserts'
1

I'm the one who is stressed.

Linda 

-----Original Message 
-----
From: programming-boun...@jsoftware.com
[mailto:programming-boun...@jsoftware.com] On Behalf Of km
Sent: Saturday, January 21, 2012 11:19 AM
To: Programming forum
Subject: Re: [Jprogramming] Morning exercise

You can sometimes vocalize hooks helpfully:  (* %) is "times the reciprocal"
and (-: |.) is "matches the reverse".  It must become instinctive to think
of the dyadic use of the first verb and the monadic use of the second.

Exercise.  How are ([: f g) and ([ f g) different from (f g) ?

Kip

Sent from my iPad


On Jan 21, 2012, at 7:57 AM, "Ken Chakahwata"
<kmchakahw...@first-derivative.com> wrote:

> I have found it easier to remember hook by considering it as special case
of
> a fork, with an appropriate identity function: i.e.
> 
>   (f g) y <=>  (] f g) y <=> (] y) f (g y)
> 
> Rgds
> Ken
> 
> -----Original Message-----
> From: programming-boun...@jsoftware.com
> [mailto:programming-boun...@jsoftware.com] On Behalf Of Marc Simpson
> Sent: 21 January 2012 10:57
> To: Programming forum
> Subject: Re: [Jprogramming] Morning exercise
> 
> On Sat, Jan 21, 2012 at 9:39 AM, Linda Alvord <lindaalv...@verizon.net>
> wrote:
>> 
>> Are there rules for specific verbs to behave differently when they are
> next
>> to each other?
> 
> I'm not sure that I understand the question-you're demonstrating hooks
> in the above; given your definitions,
> 
>   p=: -:|.
>   n=: *%
> 
> the left hand verb in the train (hook) will be called in a dyadic
> context. In other words,
> 
>   (f g) y <=> y f (g y)
> 
> as such, you're not using halve in 'p' or signum in 'n'; rather, match
> and times. Perhaps this clarifies things,
> 
>   p 23
> 1
>   (-: |.) 23
> 1
>   23 (-: |.) 23
> 1
>   23 -: |. 23
> 1
>   23 -: (|. 23)
> 1
> 
> Similarly for n,
> 
>   n 23
> 1
>   (* %) 23
> 1
>   23 (* %) 23
> 1
>   23 * (% 23)
> 1
> 
> Best,
> M
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