  Replacing symmetric powers by divided powers and working over Witt vectors
instead of ground fields, I generalize Kawamatas T^1-lifting theorem to
characteristic p>0. Combined with the work of Deligne-Illusie on degeneration
of the Hodge-de Rham spectral sequences, this gives unobstructedness for
certain Calabi-Yau varieties with free crystalline cohomology modules.
