One binary relation is the inverse of another if they are equivalent when their arguments are swapped.
(<=> (Holds ?Binary-Relation ?X ?Y) (Holds (Inverse ?Binary-Relation) ?Y ?X))
(Inherited-Facet-Value Slot-Cardinality One-One Inverse 1) (Inherited-Facet-Value Slot-Value-Type One-One Inverse Function) (<=> (One-One ?R) (And (Binary-Relation ?R) (Function ?R) (Value-Type ?R Inverse Function) (Value-Cardinality ?R Inverse 1))) (Inherited-Facet-Value Slot-Cardinality One-Many Inverse 1) (Inherited-Facet-Value Slot-Value-Type One-Many Inverse Function) (<=> (One-Many ?R) (And (Binary-Relation ?R) (Value-Type ?R Inverse Function) (Value-Cardinality ?R Inverse 1))) (Instance-Of (Function (Inverse ?R)) Not) (Not (Function (Inverse ?R))) (<=> (Many-Many ?R) (And (Binary-Relation ?R) (Not (Function ?R)) (Not (Function (Inverse ?R))))) (<- (Inverse ?Binary-Relation) (If (Binary-Relation ?Binary-Relation) (Setofall (Listof ?Y ?X) (Holds ?Binary-Relation ?X ?Y)))) (<=> (Holds ?Binary-Relation ?X ?Y) (Holds (Inverse ?Binary-Relation) ?Y ?X))