Meets:    MWF 11–11:50am,   Ross 308
Instructor:    Eric Moorhouse,   Ross 216,   766-4394.

HW2, due Mon Nov 11, is now available below.

Links/Handouts

•   Syllabus / Policies
•   Students and Teachers Working Together (UW policy on the rights and responsibilities of students and teachers)
•   UW Policy on Academic Honesty
•   HW1  due Wed Oct 2.  Solutions
•   Free groups
•   Coxeter-Todd coset enumeration in which we determine the Burnside group B(2,3) of order 27
•   GAP free software for symbolic computation with groups etc.
•   Sample GAP session from class.  I have highlighted my input in red (color not present in original computer session) to improve readability; also I have deleted sections where I mistyped.
•   HW2  due Mon Nov 11.  Solutions.  Oops, looks like I changed convention here by highlighting GAP output in red
•   Enumerating the cosets of a subgroup of index 6 in SL(2,Z)
•   Two images in the hyperbolic plane: a tessellation by triangles with angles 60, 60 and 45 degrees, and a trivalent tree (acted on by a free subgroup of index 6 in SL(2,Z))
•   Introduction to group extensions using group cohomology.  I offer also a brief introduction to cohomology which will be helpful if you haven't seen this in a more general context