fizbin

/*
 * This program solves the puzzle
 *     https://perl.plover.com/qotw/e/021
 *
 * (In case that link goes away, a brief summary of the problem
 * is to consider the free non-abelian group with 26 generators
 * 'a' through 'z', under the equivalence relation that any two
 * words found in the dictionary that are anagrams of each other
 * are equivalent. Now determine which letters commute with which
 * other letters, and specifically which letters are in the center.)