The key is that the operation (x u^:v y) is a dyad, so both arguments go to both u and v.  The function of ] [ is to DISCARD an unwanted argument.

x stuff@] y   is the same as   stuff y
x stuff@[ y   is the same as   stuff x

Thus

x stuff@] ^: [ y   is
(x&(stuff@])) ^: (x [ y) y  is
(stuff ^: x) y

The tacit language is intoxicatingly powerful.  If you just want to get a result, you can do the same thing with

   fib =: 3 : '(,+/@(_2 _1&{)) ^: y 0 1'
   fib 4
0 1 1 2 3 5

Henry Rich




On 7/20/2019 10:40 PM, The3DSquare jOsHUa wrote:
Thanks Henry and Linda

I came up with this:

fib =: (,+/@(_2 _1&{))@]^:[&0 1
    fib 8
0 1 1 2 3 5 8 13 21 34

...which works quite well.
With some rearranging, I got the two inputs on the right hand side to
switch after looking at Henry's suggestion.

Also, would you mind explaining the *]^:[* in your code, Henry? The
left/right brackets confuse me and I don't quite
understand how it moves one of the right hand side argument to the left
hand side of the conjunction.

Thanks again!




On Sat, Jul 20, 2019 at 7:08 PM Linda Alvord <[email protected]>
wrote:

Interesting!


newfib=: 13 :' }:}.(,[:+/_2&{.)  ^: y (0 1)'

    newfib 10
1 1 2 3 5 8 13 21 34 55

Linda



-----Original Message-----
From: Programming <[email protected]> On Behalf Of
The3DSquare jOsHUa
Sent: Saturday, July 20, 2019 6:11 PM
To: [email protected]
Subject: [Jprogramming] Question about ^:

Hello, I'm new to this forum. However, I have a quick question. The
conjugation ^: is represented as u ^: n y. Is there any way to make it like
u ^: y n?

Ie. Turning this:
(,[:+/_2&{.)  ^: 4 (0 1)
into this:
(,[:+/_2&{.)  ^: (0 1) 4

So essentially, swapping the two right-hand inputs for ^:.

Thanks!
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