Why should I use $[ EXPR ] instead of $(( EXPR ))?

Question

On the paragraph explaining arithmetic expansion, Bash's user guide uncovers 2 different ways of evaluating an expression, the first one uses $(( EXPRESSION )) and the second one uses $[ EXPRESSION ]. The two ways seem pretty similar as the only difference I have found is:

$[ EXPRESSION ] will only calculate the result of EXPRESSION, and do no tests:

Yet, I am intrigued because the same document recommends using $[ EXPRESSION ] rather than $(( EXPRESSION )).

Wherever possible, Bash users should try to use the syntax with square brackets:

Why would you want that if less tests are being done?

Answer 1

Duplication Question (with answer)

https://stackoverflow.com/questions/2415724/bash-arithmetic-expression-vs-arithmetic-expression

The manpage for bash v3.2.48 says:

[...] The format for arithmetic expansion is:

 $((expression)) 

The old format $[expression] is deprecated and will be removed in upcoming versions of bash.

So $[...] is old syntax that should not be used anymore

In addition to that answer:

http://manual.cream.org/index.cgi/bash.1#27

Info relating to bash versions:

Here is some info about bash man pages (its hard to find info on what version each one is referring to):

OPs link:

http://www.tldp.org/guides.html Bash Guide for Beginners version: 1.11 author: Machtelt Garrels, last update: Dec 2008

sth (74.6k rep) quoting bash v3.2.48

from https://stackoverflow.com/questions/2415724/bash-arithmetic-expression-vs-arithmetic-expression)

Note: More info about [] vs (()) here: http://lists.gnu.org/archive/html/bug-bash/2012-04/msg00033.html

a link I found:

http://www.gnu.org/software/bash/manual/ last updated August 22, 2012

http://www.gnu.org/software/bash/manual/bash.html#Arithmetic-Expansion