Expression Question about DL

Dear Sir or Madam:

     I have difficulty in writing such assertions in Description Logic.

At first, I have three assertions,

1: Every Presentation is made by a Person.  

2: Every Paper is introduced at a Presentation.

3: Every Paper is (mainly) written by a Person.

I can write them in DL as below:



But I can not write an assertion to state that 

4: Every Paper is introduced at a Presentation by the paper's writer,

 

     Sincerely appreciate any suggestion!

                                 

                                                        Cai Shubin