1. Certain cell-like maps of S^4 with zero-dimensional singular sets are approximable by homeomorphisms. An exposition of a theorem of M. Freedman. [pdf]

2. A counterexample to a geometric general position conjecture. [pdf]

3. 2-dimensional axiomatic geometry revisited.Outline. [pdf]

4. Unknotable Sets. [pdf]

5. A topological proof of the Primitive Element Theorem and the omegatator of a free group. [pdf]

6. Surface Games. [pdf]

7. Topological elements of geodesic spaces. [pdf]

8. Are all high-dimensional contractible open manifolds Gabai splittable? [pdf]

9. Ancel-Siebenmann, The construction of homogeneous homology manifolds, Abstracts Amer. Math. Soc. 6 (1985), 92. [pdf]

10. Engulfing the Track of a Proper Homotopy. [pdf]

11. Cell-like maps and the Kozlowski-Walsh Theorem – some alternative proofs. [pdf]

12. Visual boundaries of Davis manifolds. [pptx]

13A. Symmetry, Orbifolds and the Alhambra Mosaics A – UWM Topology Seminar. [pptx]

13B. Symmetry, Orbifolds and the Alhambra Mosaics B – UWM Topology Seminar. [pptx]

14. Most unexposed taut one-relator presentation 2-complexes are finitely unsplittable, with P. Sparks, [pdf]

15. Recursively squeezable sets are squeezable. [pdf]

16. On the isometrization of groups of homeomorphisms. [pdf]

17. Semi-isotopic knots. [pdf]