Daniel Fischer wrote:
class BEING human => HUMAN human where Sub-classing is logical implication BEING(human) => HUMAN(human) All types t that make BEING(t) = true also make HUMAN(t)=true
No, it's the other way round. Every HUMAN is also a BEING, hence
HUMAN(t) => BEING(t)
Could I say that HUMAN is a subset of BEING?
That depends on whether predicates are sets.. But yes, every instance of HUMAN is also an instance of BEING, hence, the set of HUMAN instances is a subset of the set of BEING instances.
In the light of the above examples how should I interpret the class-to-subclass relation as logical implication? Is it a) If BEING then HUMAN (sufficient condition): BEING => HUMAN b) HUMAN is true only if BEING (necessary condition): HUMAN => BEING c) Neither?
b). Every HUMAN is a BEING. Cheers, Sebastian -- Underestimating the novelty of the future is a time-honored tradition. (D.G.)