What does the vertical pipe slash operator do? I'm wondering what pipe slash |/ does in,

SET equal_area_radius = |/area/pi();


The statement works and it definitely changes the value:

SELECT |/125.555/pi(); --  returns: 6.32181918120139
SELECT 125.555/pi();   --  returns: 39.9653977598058


What does the pipe-slash operator |/ do?
The |/ operator calculates the square root

postgres&gt;  select |/16,  sqrt(16);
 ?column? | sqrt
----------+------
        4 |    4
(1 row)


So |/125.555/pi() is equivalent to sqrt(125.555/pi())