Taking the trace with respect to the metric of both sides of the EFE one gets R − − D 2 R + D Λ Λ = κ κ T , where D is the spacetime dimension. Solving for R and substituting this in the original EFE, one gets the following equivalent "trace-reversed" form: R μ μ ν ν − − 2 D − − 2 Λ Λ g μ μ ν ν = κ κ ( T μ μ ν ν − − 1 D − − 2 T g μ μ ν ν ) .