runTest :: IO [String]
runTest = return [
  str (a/a), str (a/b), str (a/c),
  str (b/a), str (b/b), str (b/c),
  str (c/a), str (c/b), str (c/c)]
runTest :: IO [String]
runTest = return [
  str (a/a), str (a/b), str (a/c),
  str (b/a), str (b/b), str (b/c),
  str (c/a), str (c/b), str (c/c)]
runTest = return [
  str (a/a), str (a/b), str (a/c),
  str (b/a), str (b/b), str (b/c),
  str (c/a), str (c/b), str (c/c)]