[Jprogramming] Untying the Gordian Knot: Agreement in J

[Roger Hui]

   3 4 5 $"3j4 'abc'
|domain error
|   3 4 5    $"3j4'abc'

   3 4 5 $"'1' 'abc'
|domain error
|   3 4 5    $"'1''abc'

   3 4 5 $"1 2 3 4 'abc'
|length error
|   3 4 5    $"1 2 3 4'abc'

    3 4 5 $"(,.2) 'abc'
|rank error
|   3 4 5    $"(,.2)'abc'



----- Original Message ----- 
From: "June Kim" <juneaftn at gmail.com>
To: "Programming forum" <programming at jsoftware.com>
Sent: Friday, March 31, 2006 11:03 PM
Subject: [Jprogramming] Untying the Gordian Knot: Agreement in J

Hello

I have been reading Martin Neitzel's paper on verb ranks from APL
Quote Quad '95. That helped me deepen my understanding on the subject,
though I don't feel completely secure with my understanding yet.

On section 10 Excercises for Rank, there is a problem answered at the end:

[quote]
The reshape verb $ has dyadic ranks (1 _). It is no problem to
evaluate 3 2 4 $ 'abc', but try to find some invalid rank
specification n in 3 2 4 $"n 'abc'!
[/quote]

I couldn't come up with such n that throws an error. Any ideas?