STACK

$A|Ax|K|S\ I\ --\ X$
$D\ X\ --\ X$

DESCRIPTION

Red book operator returns a single element from the value of the first operand.
If the first operand is an array, stack or a string, get treats the second operand as an index and returns the element identified by I,
counting from 0. I must be in the range 0 to n - 1, where n is the length of the array, stack or string.
If the first operand is a dictionary, get looks up X as a key in the dictionary and returns the associated value.

ORIGIN

Core code registered in systemdict.