Editing List of undecidable problems (section)

==Problems in topology==
{{Main|Simplicial complex recognition problem}}
* Determining whether two finite [[simplicial complex]]es are [[homeomorphic]].
* Determining whether a finite [[simplicial complex]] is (homeomorphic to) a [[manifold]].
* Determining whether the [[fundamental group]] of a finite simplicial complex is trivial.
* Determining whether two non-[[simply connected]] [[5-manifold]]s are homeomorphic, or if a 5-manifold is homeomorphic to '''S'''<sup>5</sup>.<ref>{{citation|title=Classical Topology and Combinatorial Group Theory|volume=72|series=Graduate Texts in Mathematics|first=John|last=Stillwell|authorlink=John Stillwell|publisher=Springer|year=1993|isbn=9780387979700|page=247|url=https://books.google.com/books?id=265lbM42REMC&pg=PA247}}.</ref>