Learn You Some Erlang: List Comprehensions uses “in” - and it does set up the association between ∈ and <- though it isn’t explicit about. Personally I’ve always pronounced ∈ as “element of”.
Designing for Scalability with Erlang/OTP p.27
The effect of this is to successively bind the variable
Xto the values2, 3, 5, 7, and 11. In other words, it generates the elements from the list: the symbol<-is meant to suggest the “element of” symbol for sets, ∈.
Erlang Programming - A Concurrent Approach to Software Development p.198
Generators
A generator has the formPattern <- List, wherePatternis a pattern that is matched with elements from theListexpression. You can read the symbol<-as “comes from”; it’s also like the mathematical symbol ∈, meaning “is an element of”.
