enumeration

senum_decl:=
type_declarations | enum sdeclname { senum_items }
sopt_value:=
type_declarations | = INTEGER
type_declarations | epsilonnone
senum_item:=
type_declarations | NAME sopt_value
senum_items:=
type_declarations | senum_item , senum_items
type_declarations | senum_item
type_declarations | epsilon