A KB dependent collection of set-or-collections of set-or-collections; a specialization of type of Cyc set or collection. A sibling-disjoint set-or-collection type is such that its known (i.e. KB-represented) elements are set-or-collections that -- save for any that are related to each other by subset and any that are explicitly asserted to be exceptions (see Sibling Disjoint Exceptions) -- are disjoint from each other (see No).

More precisely, each instance SIB of sibling disjoint set or collection type is a intensional or extensional set of SetOrCollections that has the following KB-dependent property:

For any two known elements SETORCOL1 and SETORCOL2 of SIB, at least one of the following is known to hold:

  (a) (subset SETORCOL1 SETORCOL2)
  (b) (subset SETORCOL2 SETORCOL1)
  (c) (Sibling Disjoint Exceptions SETORCOL1 SETORCOL2)
  (d) (No SETORCOL1 SETORCOL2)

Moreover, note that if MT is a context (see context) in which (i) both (Element Of SETORCOL1 SIB) and (Element Of SETORCOL2 SIB) hold and (ii) neither (subset SETORCOL1 SETORCOL2) nor (subset SETORCOL2 SETORCOL1) nor (Sibling Disjoint Exceptions SETORCOL1 SETORCOL2) is known to hold (see Known Sentence), then (No SETORCOL1 SETORCOL2) holds by default in MT.

Cf. the stronger notion of disjoint set or collection.