17. A medium as in claim 13 , wherein said comparing comprises: determining a similarity indicator from said mathematical representation of said document and said collective mathematical presentation.
17. A medium as in claim 13 , wherein said comparing comprises: determining a similarity indicator from said mathematical representation of said document and said collective mathematical presentation. 18. A medium as in claim 17 , wherein said mathematical representation of said document and said collective mathematical presentation are vectors; and, said similarity indicator is based on a dot product of said vectors.