text: Ko te taketake i whakaarotia e Henri Poincare, e whakaaro ana te whakatakoto ki tētahi mokowā e āhua ana ki te mokowā ahu-toru noa, engari kua tūhonotia, paetata te rahi, ā, kāore he rohenga (he kōpaki-3-manifold kua katia).