code: def _ij_ik_il_to_jkl(a, b, c):
      ab = chainer.functions.matmul(a[:, :, None], b[:, None, :])  # ijk
      return chainer.functions.matmul(_as_mat(ab).T, c).reshape(
          a.shape[1], b.shape[1], c.shape[1]
      )
  
imports: import numpy
  import chainer
  from chainer import backend
  from chainer import function_node
  from chainer.utils import type_check
label_desc: Use image node_id 2 for calling a global function with example usage: _ij_ik_il_to_jkl(a, b, c) and returns: chainer