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Thus, the problem reduces to finding the signs of g ′′ $_{00}$( r$_{0}$ ) and g ′′′ $_{00}$( r$_{0}$ ). Using the software Maple we find the following numerical values g ′′ $_{00}$( r$_{0}$ ) ≈ 0 . 287 and g ′′′ $_{00}$( r$_{0}$ ) ≈ − 0 . 277. This implies that the coordinate singularity r$_{0}$ is at p = −∞ and q = ∞ when we move toward it from r > r$_{0}$ and at p = ∞ and q = −∞ when we approach it from r < r$_{0}$ , keeping in mind that these two regions will be covered by two different coordinate patches. With respect to the first coordinate patch the spatial infinity is at p = ∞ and q = −∞ . Again we can make the infinities finite by means of the transformation p = tan P and q = tan Q , the nice feature of which is that we can lay the images of r = r$_{0}$ side by side in the two patches. With respect to the coordinate patch in the region r > r$_{0}$ the image of r = r$_{0}$ is the point with coordinates P = − π/ 2 and Q = π/ 2 whereas the choice of the coordinate patch relative to the region r < r$_{0}$ sends r$_{0}$ to P = π/ 2 and Q = − π/ 2. in passing we note that spacelike infinity is mapped also to the point ( π/ 2 , − π/ 2) in the ( P, Q )-plane. Putting 

