- Non-simply connected 5-manifolds are impossible to classify, as this is harder than solving the word problem for groups.
Does that mean the word problem for groups is actually reducible to the problem of classifying non-simply connected 5-manifolds? Michael Hardy 22:02, 3 November 2006 (UTC)
Wouldn't it be more appropriate to merge this article with some other manifold-related article? Maybe Manifold, or maybe merge the 4- and 5-manifold articles together. It just seems like there isn't much content here. Gandalf (talk) 19:09, 3 October 2008 (UTC)