TensorProductDecomposition( module, basis, d1, d2 )
module is a module for a matrix group G over a finite field, basis is a basis of the underlying vector space, d1 and d2 are two integers whose product is the dimension of that space.
TensorProductDecomposition returns true if module can be decomposed
as a tensor product of spaces of dimensions d1 and d2 with respect to
the given basis, and false otherwise. The matrices which represent the
action of the generators of G with respect to the appropriate basis are
computed.
TensorProductDecomposition is called by SmashGModule.
The algorithm is described in [6].
GAP 3.4.4