Definition:Equivalence class

Definition: Equivalence class
If is an equivalence relation on a set , then the equivalence class of by (written ) is the set of elements with .

In other words,

Note: I usually use the symbols [ and ] instead of ⟦ and ⟧, but the wiki syntax makes this difficult. You may use either notation.

When is clear from context, we just write ⟦a⟧.