  A new representation of the Einstein evolution equations is presented that is
first order, linearly degenerate, and symmetric hyperbolic. This new system
uses the generalized harmonic method to specify the coordinates, and
exponentially suppresses all small short-wavelength constraint violations.
Physical and constraint-preserving boundary conditions are derived for this
system, and numerical tests that demonstrate the effectiveness of the
constraint suppression properties and the constraint-preserving boundary
conditions are presented.
