Words in the Symplectic Group (9/28/05)

This was a talk on some research I was doing at the time. I was basically trying to modify Riley's methods in order to construct short words in Sp(2g,Z) for g at least 2. Shortly thereafter, I was told by Kassabov that for g at least 3 this construction follows immediately from Riley's, but to this day I'm not sure why this is true. Perhaps someone will find the g=2 case interesting?