text: from pcsptools import *
  
  
  try:
      solution = next(test_identities(
          cycle(5), clique(4), parse_identities("c(xyz) = c(yzx)")))
      assert(False)
  except StopIteration:
      pass
  
  try:
      solution = next(test_identities(
          onein(3), nae(2), parse_identities("p(xxy) = p(yxx) = p(yxy) = p(yyy)")))
  except StopIteration:
      assert(False)
  
  try:
      solution = next(test_identities(
          affine(2), affine(2),
          parse_identities(
              "u(xxy) = u(xyx) = u(yxx) = d(xy)",
              "v(xxxy) = v(xxyx) = v(xyxx) = v(yxxx) = d(xy)")))
      assert(False)
  except StopIteration:
      pass
  
  try:
      solution = next(test_identities(
          hornsat(), hornsat(),
          parse_identities(
              "d(xy) = d(yx) = t(xxy) = t(xyy)",
              "t(xyz) = t(yzx)")))
  except StopIteration:
      assert(False)
  