Sigma KB Term Intersection

No TPTP formula. May not be expressible in strict first order.	Merge.kif 828-830	If a class is an instance of class, then the class is a subclass of entity
No TPTP formula. May not be expressible in strict first order.	Merge.kif 137-141	If a class is a subclass of another class, then the class is an instance of class and the other class is an instance of class
No TPTP formula. May not be expressible in strict first order.	Merge.kif 2136-2136	Class is a subclass of set or class
No TPTP formula. May not be expressible in strict first order.	Merge.kif 131-131	The number 1 argument of subclass is an instance of class
No TPTP formula. May not be expressible in strict first order.	Merge.kif 132-132	The number 2 argument of subclass is an instance of class