# When an expression has double brackets in it ($[[x]]$), what type of expression is this? [closed]

I am curious to know what type but I know that one is greatest integer parent function. There is another one that explains it and I want to know what another function represents that?

Double square brackets $$[\![a, b]\!]$$ are used also to mean the interval of all integers between a and b included.
I feel that your answer is here : https://in.answers.yahoo.com/question/index?qid=20090710203054AA3mCg9 Here, it is said that the double brackets ($$[[x]]$$) mean rounding off, to be frank.