Understanding of brackets placement

[n10ty]

I need to sync my understanding of how and why rulerz place brackets. Below you can see several examples.
Condidtion:
$rules = '1 = 1 and 1 = 1 and 1 = 1 or 1 = 1';
Result in query:
WHERE ((1 = 1 AND (1 = 1 AND (1 = 1 OR 1 = 1))))

Condition:
(1 = 1) and ((1 = 1) or (1 = 1) or (1 = 1)) and (1 = 1 or 1 = 1 or 1 = 1)
Result:
((1 = 1 AND ((1 = 1 OR (1 = 1 OR 1 = 1)) AND (1 = 1 OR (1 = 1 OR 1 = 1)))))

In the second example, it increases the deep of Doctrine query. In result: simple condition becomes enormous.
So, I have a situation where I need only a lot of conditions joined with OR, but after adding brackets it becomes 256 nested level error.
I don't understand it. Is it always add brackets? How should I avoid this? Why it so? What is the main idea of it? I didn't find any mention of this case in documentation. Thank for your answer, your library is really great.