Editing Geometrization conjecture (section)

===The geometry of S<sup>2</sup> × R===
The point stabilizer is O(2, '''R''') × '''Z'''/2'''Z''', and the group ''G'' is O(3, '''R''') × '''R''' × '''Z'''/2'''Z''', with 4 components.  The four finite volume manifolds with this geometry are: '''S'''<sup>2</sup> × '''S'''<sup>1</sup>, the mapping torus of  the antipode map of '''S'''<sup>2</sup>, the connected sum of two copies of 3-dimensional projective space, and the product of '''S'''<sup>1</sup> with two-dimensional projective space. The first two are mapping tori of  the identity map and antipode map of the 2-sphere, and are the only examples of 3-manifolds that are prime but not irreducible. The third is the only example of a non-trivial connected sum with a geometric structure. This is the only model geometry that cannot be realized as a left invariant metric on a 3-dimensional Lie group. Finite volume manifolds with this geometry are all compact and have the structure of a [[Seifert fiber space]] (often in several ways). Under normalized Ricci flow manifolds with this  geometry converge to a 1-dimensional manifold.