Is there a mistake in the Frame-Layer explanation?

Hallo!

 

My Name is Matthias. I'm a computer-science student from Karlsruhe, Germany.
At present I work on my diploma these which deals with dynamic workflows
based on semantic service descriptions. Therefore I study the SWSF, more
precisely, the SWSL at present. There's the following explanation in the
Frame-Layer section:

 

-for signatures:

Signatures obey the laws of monotonic inheritance, which are as follows: 

*         t:s and s[m *=> v] entails t[m *=> v] 

*         t::s and s[m *=> v] entails t[m => v] 

These laws state that type declarations for inheritable methods are
inherited to subclasses in an inheritable form, i.e., they can be further
inherited. However, to the members of a class such declarations are
inherited in a non-inheritable form. Thus, inheritance of signatures is
propagated through subclasses, but stops once it hits class members

-for values:

Inheritance of value molecules is more involved. This type of inheritance is
nonmonotonic and it can be overridden if the same method or attribute is
defined for a more specific class. More precisely, 

*         t:s and s[m *-> v] entails t[m *-> v]   unless overridden or in
conflict 

*         t::s and s[m *-> v] entails t[m -> v]   unless overridden or in
conflict 

Similarly to signatures, value molecules are inherited to subclasses in the
inheritable form and to members of the classes in the non-inheritable form.

Is the explanation not vice versa to their laws? Shouldn't it sound like
this: ".type declarations for inheritable methods are inherited to
subclasses in a non-inheritable form, i.e., they can't be further inherited.
However, to the members of a class such declarations are inherited in an
inheritable form."? Or are the laws incorrect? If I'm wrong, I'm sorry. In
this case, it would be very kind, if someone can give me a more detailed
explanation of the laws. Thank you!

Kind regards

Matthias Racke

 

Received on Friday, 20 January 2006 08:58:31 UTC