**Defined in theory: Frame-ontology****Source code: frame-ontology.lisp**

**Documentation:**The VALUE-TYPE of a binary relation R with respect to a given instance d is a constraint on the values of R when R is applied to d. The constraint is specified as a class T such that when R(d,t) holds, t is an instance of T.

**Arity:**3

(Nth-Domain Value-Type 3 Class) (Nth-Domain Value-Type 2 Binary-Relation) (<=> (Value-Type ?Instance ?Binary-Relation ?Type) (And (Binary-Relation ?Binary-Relation) (Class ?Type) (Forall (?Value) (=> (Holds ?Binary-Relation ?Instance ?Value) (Instance-Of ?Value ?Type)))))

- VALUE-TYPE is convenient for specifying type restrictions on slots relative to a class by using the class's instance variable.
**See-Also:**slot-value-type