If is_a_type is a derivable type, check whether type is a descendant of is_a_type. If is_a_type is an interface, check whether type conforms to it.
Type to check anchestry for.
Possible anchestor of type or interface type could conform to.
TRUE if type is_a is_a_type holds true.
See Implementation
If is_a_type is a derivable type, check whether type is a descendant of is_a_type. If is_a_type is an interface, check whether type conforms to it.