import tensorflow as tf

        layer_id, tf.matmul(next_h[-1], self.w_attn_1))

    def _condition(layer_id, *args):
      return tf.less(layer_id, self.num_cells + 2)

    def _body(layer_id, inputs, prev_c, prev_h, anchors, anchors_w_1, arc_seq,
              entropy, log_prob):
      indices = tf.range(0, layer_id, dtype=tf.int32)
      start_id = 4 * (layer_id - 2)
      prev_layers = []
      for i in range(2):  # index_1, index_2
        next_c, next_h = stack_lstm(inputs, prev_c, prev_h, self.w_lstm)
        prev_c, prev_h = next_c, next_h
        query = anchors_w_1.gather(indices)
