- ... equations
^{1} - In the BSSN formalism a set of auxiliary
connection functions is introduced that simplify the
three-dimensional Ricci tensor
in the same way as
the simplify the four-dimensional Ricci tensor
in the formalism adopted by Pretorius.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .