Re: [Bug-apl] What do Quad-slash and Quad-Backslash do?

[Nick Lobachevsky]

Generally every APL vendor added extra features into their version of
the language, sometimes to accommodate new hardware or environments,
sometimes to enhance their competitive advantage.

Burroughs and one or another DEC APL used cute quad-something glyphs,
mostly for their file system operations.  Maybe it was early IBM APL2
which had the eigenvalue glyphs.  Or possibly the paper was a proposal
to add the eigenvalue functionality and glyphs to the language.

On 20/07/2015, Jay Foad <address@hidden> wrote:
> What's the paper? Does it say which APL they were using?
>
> On 19 July 2015 at 16:25, <address@hidden> wrote:
>
>> Hi Bug APL,
>>
>> I found a paper that computes eigenvalues using the following equation
>> eig←{t[;⍒(t←⍂⍵)[0;]]}
>>
>> where ⍵ is a matrix of coefficients.
>>
>> It looks like the symbols are in the unicode standard, but I have never
>> seen a definition before:
>> ⍁
>> U+2341
>> &#x233C;
>> APL Functional Symbol Quad Slash
>> ⍂
>> U+2342
>> &#x2342;
>> APL Functional Symbol Quad Backslash
>>
>