Derrick Stolee
J. L. Doob Research Assistant Professor
Department of Mathematics
University of Illinois at Urbana-Champaign








SearchLib is a collection of projects with a common goal: search for combinatorial structures. Each project is customized to the problem at hand, but there are common elements. The first is the use of TreeSearch for the structure of the search, giving a common interface for all input/output management and statistics tracking. The second is the consideration of symmetries of the objects. To compute automorphisms and canonical labelings, we use Brendan McKay's nauty software. The most recent stable version of SearchLib can be downloaded on a project-by-project basis. The nauty library must be downloaded separately to comply with licenses.
TreeSearch   An abstract implementation of a backtracking search to allow automatic parallel job generation. Includes scripts for input/output management on a grid using the Condor scheduler. Forms the base of all other projects in SearchLib.   Source User Guide
Utilities   This package contains classes, methods, and executables that are used by other projects.   Source User Guide
EarSearch   Generates 2-connected graphs by ear decompositions using an isomorph-free generation scheme. Requires: nauty.   Source User Guide
ChainCounting   Generates width-two posets and counts the number of chains in each, searching for representations of all positive integers. Found representations for all integers up to 7.38 million. Joint work with Elizabeth Kupin and Benjamin M. Reiniger.   Source User Guide
Saturation   Generates uniquely Kr-saturated graphs using a custom augmentation. Uses orbital branching or isomorph-free generation. Found several new graphs of orders 13, 15, 16, and 18 and a new infinite family. Requires: nauty and cliquer. Joint work with Stephen G. Hartke.   Source User Guide
Progressions   Searches for extremal colorings of [n] which avoid different types of progressions which generalize arithmetic progressions. Also restricts to symmetric colorings of [n]. Joint work with Adam S. Jobson and André E. Kézdy.   Source User Guide
MMSConjecture   Searches for vectors of $n$ real numbers with non-negative sum while minimizing the number of non-negative partial $k$-sums. Verifies the Manickam-Miklós-Singhi Conjecture for $k \leq 7$. Joint work with Stephen G. Hartke. Source User Guide
This software was created with support from the National Science Foundation, grants CCF-0916525 and DMS-0914815.