9.1.4 Interface Body and Member Declarations

The body of an interface may declare members of the interface:

InterfaceBody:
{ InterfaceMemberDeclarationsopt }
InterfaceMemberDeclarations:
InterfaceMemberDeclaration
InterfaceMemberDeclarations InterfaceMemberDeclaration
InterfaceMemberDeclaration:
ConstantDeclaration
AbstractMethodDeclaration

The scope of the name of a member declared in an interface type is the entire body of the interface type declaration.