extend rdfs:Class & rdf:Property

Hello,

The 11th rule in the RDF Model Theory which states that if
xxx rdfs:subClassOf yyy   and aaa rdf:type xxx .
then aaa rdf:type yyy
does this rule applies if xxx is subclass of  rdfs:Class?

More precisely, if the following facts are stated:
the  class MyClass is subClassOf rdfs:Class and C1 is instance of  MyClass
i.e.,
<rdfs:Class rdf:ID="MyClass">
<rdfs:subClassOf
  rdf:resource="http://www.w3.org/2000/01/rdf-schema#Class"/>
</rdfs:Class>

<MyClass rdf:ID="C1"/>

can I infer that C1 is a class? Or it is should be explicitly stated in
the RDF file that C1 is instanceof rdfs:Class?

Repsectively, if I define a class MyProperty as subclass of rdf:Property
and P1 is instance of MyProperty i.e.,

<rdfs:Class rdf:ID="MyProperty">
<rdfs:subClassOf rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property"/>
</rdfs:Class>

<MyProperty rdf:ID="P1"/>
can I infer that P1 is a property?

Regards,
Sofia Alexaki