SSL Minutes for Tuesday, Nov. 4, 2003
Note-taker: Hal
Snacks: Emilie
Paul will take notes next time.
Abby will bring snacks next time.
Everyone seemed to be here except for Stephen, who was an hour late.
We started in B107.
Someone brought up graph.tcl. How to use it under Windows. First,
get the newer version
http://jamespropp.org/alt/graph.tcl
Get TCL from ActiveState:
http://www.activestate.com/Products/ASPN_Tcl/
To delete vertices, click both mouse buttons.
The link
http://jamespropp.org/SSL/private/Projects-2003
from
http://jamespropp.org/SSL/private/
doesn't work. Jim will delete them. Maybe add a link to before.mws.
Next time: Paul will take notes, and Abbie will bring snacks.
We all got accounts at undergrad.math.wisc.edu cluster. I noticed
that it was firewalled off. This has now been fixed.
Summaries:
Martin looked at the cube snake recurrence. To remind us, we had
found that the recurrence was two known sequences interleaved. We want
to find a nice bijection for them. (*)
Carl is interested in that problem (*), but hasn't done much with it.
John infected Carl with an unrelated math problem. He apologizes.
John looked at face matching of cube snakes. Here is the question:
"If a snake is heading in the x direction and bend into the y direction
and then back to the x direction, does it have the same number of
matchings as a cube that is heading in the x direction and bend into
the y direction and then into the z direction?" John claims that the
answer is yes for face matchings and no for edge matchings (using
graph.tcl to find a counterexample).
Paul wants to work on the bijection problem (ref *) in a group. He also
studied the Laurent polynomials. He found a sequence of numbers (from
coefficients of Laurent polynomials) that were not in the handbook.
Should he submit them to the Handbook. Jim says to look into the
procedure for that.
Sam looked at (*), Also reading Itsara Article. We agree that
Markoff snakes are a subset of snakes that, among other properties
never bend left and immediately right. They are also symmetric under
180 degree rotation. He also looked at Somos sequences.
Emilie solved the equations from the triangle system that Jim talked
about last week.
Hal talked about where to go with the Soddy Relation.
Abby looked at the relationship between dominoes and cube snakes. She
got half of the bijection (*).
We break up and work on different things.