Haskell <- list comprehension

So, is the <- in Haskell list comprehension an arrow (as in, ``take the x from''), or does it imitate the ∈ character from the mathematical set notation?
e.g. {x² : x ∈ ℕ} and [x | x <- [0,1..]]).

>>1
use prolog.

>>11
http://foldoc.org/index.cgi?query=array&action=Search
A collection of identically typed data items distinguished by their indices (or "subscripts"). The number of dimensions an array can have depends on the language but is usually unlimited.

http://foldoc.org/index.cgi?lists
A data structure holding many values, possibly of different types, which is usually accessed sequentially, working from the head to the end of the tail - an "ordered list".