U+2218 "∘" Ring Operator Unicode Character

U+2218 "∘" Ring Operator is a mathematical symbol commonly used to represent function composition, meaning that applying the operator to two functions f and g yields a new function that applies g first and then f, denoted as (f ∘ g)(x) = f(g(x)). It also appears in algebra, category theory, and logic to denote binary operations such as the composition of relations or the Hadamard product in matrix algebra. This character is distinct from the degree sign and the superscript lowercase letter o, as it is specifically designed for mathematical notation with consistent spacing and placement.