Generic classes derived from other generic classes do not draw their relationship

Example:
protocol ProtocolF {
associatedtype T
var b1: T? { get }
}

class ClassF<Type,TypeB,TypeC> : ProtocolF {
var b1: Type?
var b2: TypeB?
var b3: TypeC?
}

class ClassG<Type,TypeB,TypeC,TypeD>: ClassF<Type,TypeB,TypeC> {
var b5: Type?
var b6: TypeB?
var b7: TypeC?
var b8: TypeD?
}