Writer's Algebra

There is an equation every writer has to work out for themselves.  That equation is how long can I glue my ass to this chair and type before my butt goes numb?  It has constants – number of words to be typed, the number of hours in the day.  It has differentials, such as how much lumbar support you have, how cushiony your seat, or how often you cross and uncross your legs.

And I have been attempting to perfect this equation all week.

Luckily, I recently found a coffee shop in Los Angeles with v...