An arm is a named Hoon expression in a core. A core contains one or more arms. If a core is thought of as an object in an object-oriented language, its arms can be thought of as its methods.

Arms are one of the two types of wing in the subject, the other being a leg.

Further Reading

• Hoon School: Our guide to learning the Hoon programming language.
  • “Cores”: A Hoon Tutorial lesson that discusses cores.