A domain instance i CAN-HAVE-ONE value for a slot R if there is at most 1 value v for which R(i,v) holds.Asserting (CAN-HAVE-ONE ?i R) in the definition of some class C, where ?i is the instance variable for that class, is another way of specifying that C is a domain restriction of R and R is a single-valued-slot on C.
Notes:
- See-Also: has-at-most single-valued-slot domain
(<=> (Can-Have-One ?Instance ?Binary-Relation) (Has-At-Most ?Instance ?Binary-Relation 1))