Please consider my note "A Note on the Unitarity Property of the Gassner
Invariant" for publication in these proceedings. It is available at
http://drorbn.net/AcademicPensieve/2014-06/UnitarityOfGassner/UofG.pdf.

Only the first 3 pages of the note are to be considered for publication;
the 4 pages after that are a mathematica notebook that is mentioned in the
paper and is available on the web, and it is attached only for your and
the referee's convenience.

Best,

Dror.