On 3 March 2016 at 08:12, Elias Mårtenson <[email protected]> wrote:
> What is the purpose of the double-enclose ⊂⊂⍬ ?
>
> My understanding was that (⊂⊂x)≡⊂x for all x?
No! ⊂ is a no-op on simple scalars like 42, but not on enclosures like
⊂⍬. You can enclose most arrays (i.e. anything except simple scalars)
as many times as you like, and they keep getting deeper and deeper.
Hmm, now I see that GNU APL seems to be broken. In APL2 and Dyalog and
NARS2000 I get:
≡⊂⊂⊂⊂⊂⊂⊂⊂⊂'elias'
10
But in GNU APL:
≡⊂⊂⊂⊂⊂⊂⊂⊂⊂'elias'
2
Jay.
