entity Blog {
    title: String
    body: String
}

entity Author {
    name: String
}

association R1 {
    Each Blog "is written by" exactly one Author
    Each Author "may write" zero or more Blogs
}

Relationship:
	'Relationship' name=ID '{'
	(roles+=RelRole)*
	'}';

RelRole:
	'Each' class1=[Entity] relPhrase=STRING multiplicity=Multiplicity class2=[Entity] ;

Multiplicity:
	"at most one" | "exactly one" | "zero or more" | "one or more"
;

Each Author "may write" zero or more Blog

'entity' name=ID ('plural' plural=ID)? // ..etc.