| | 1 | === Base Template !InstanceOfRelation === |
| | 2 | |
| | 3 | [[br]]This is a template for expressing relationships that do not have a predefined ISO 15exists 26-2 type. |
| | 4 | [[br]]!InstanceOfRelation(a, b, c) means that a is a custom-defined relation by which b is related to c. |
| | 5 | [[br]] |
| | 6 | [[br]]Roles: |
| | 7 | [[br]]1 hasRelation !ClassOfRelationshipWithSignature |
| | 8 | [[br]]2 hasFirstElement Thing |
| | 9 | [[br]]3 hasSecondElement Thing |
| | 10 | |
| | 11 | Axiom: |
| | 12 | {{{ |
| | 13 | InstanceOfRelation(x1, x2, x3) <-> |
| | 14 | ClassOfRelationshipWithSignature(x1) & |
| | 15 | Thing(x2) & |
| | 16 | Thing(x3) & |
| | 17 | exists u(OtherRelationshipTriple(u, x2, x3) & |
| | 18 | ClassificationOfRelationship(u, x1)) . |
| | 19 | }}} |
| | 20 | |
| | 21 | NOTE This template uses the template !ClassificationOfRelationship. Where the latter template takes an |
| | 22 | ordered pair (a relationship) as a single argument to be classified by a relation, this template |
| | 23 | takes the elements of the ordered pair themselves as arguments. The composition of these elements into |
| | 24 | an ordered pair is given by the template axiom. |
| | 25 | |
| | 26 | EXAMPLE Let Alfred and ACME Co. be instances of Person, and Employment a custom-defined relation (i.e., a !ClassOfRelationshipWithSignature). |
| | 27 | |
| | 28 | Note that |
| | 29 | — no designation for the classified ordered pair is defined, |
| | 30 | — the definition of the !ClassOfRelationshipWithSignature, which should include specification of roles for the ends of the relation, is not given in the template statement. |
