This post shows an example of General Class Axiom:
((walksLike some Duck) and (talksLike some Duck)) SubClassOf Duck
Isn't it the same as giving a necessary and sufficient condition on Duck?
Duck EquivalentTo: ((walksLike some Duck) and (talksLike some Duck))
Aren't they logically equivalent? I've read this article as well, but I don't understand what General Class Axiom's real use for.
The subsumption provides only one of necessary
or sufficient
, as AKWS remarked.
Example:
A1 instanceOf Duck
A2 instanceOf (walksLike some Duck)
A2 instanceOf (talksLike some Duck)
With just the subsumption axiom, the queries:
Instances of Duck
: A1, A2
Instances of walksLike some Duck
: A2
With the equivalence axiom:
Instances of Duck
: A1, A2
Instances of walksLike some Duck
: A1, A2