On 06/11/2019 17:05:21, Martin Euredjian via Python-ideas wrote:
  One has to use APL for real work and for at least a year or two in order for your brain to make the mental switch necessary to understand it.  Just messing with it casually isn't good enough.  Lots of inquisitive people have messed with it, but they don't really understand it.

No offence, but my honest off-the-cuff reaction:
The above could be interpreted as
"APL is a difficult language to learn, it takes at least a year or two of real work with it in order for your brain to make the mental switch necessary to understand it.
As opposed to more intuitive languages, such as ... I don't know ... I'm sure there's one beginning with P."
In today's fast-moving world we can't afford that "year or two" before we are really productive.
Nor to write code that other people need "a year or two" before they can read it fluently.

Disclosure: I have no experience with APL.

I did click on your "Notation as a Tool of Thought" link, but I didn't get very far with it before my eyes glazed over looking at all the unfamiliar symbols.
(This although I call myself a mathematician of sorts - not someone who throws a fit at the sight of equations or Greek letters.)

Yes, it would have been nice if <- had been included in the ASCII character set when it was developed in the 1960s;
then all programming languages could use <- for assignment and = for equality.  (Where is the time machine when you need it?)
But regrettably, we are where we are.
And having to type Alt-[ for every assignment - virtually necessitating the use of both hands -
would IMO be a significant inconvenience.

Best wishes
Rob Cliffe