Department of Mathematics, Statistics, and Computer Science, Macalester College, Saint Paul, Minnesota, United States of America. ctopaz@macalester.edu|Department of Mathematics, Statistics, and Computer Science, Macalester College, Saint Paul, Minnesota, United States of America. ctopaz@macalester.edu|Department of Mathematics, Statistics, and Computer Science, Macalester College, Saint Paul, Minnesota, United States of America. ctopaz@macalester.edu|Department of Mathematics, Statistics, and Computer Science, Macalester College, Saint Paul, Minnesota, United States of America. ctopaz@macalester.edu