import tensorflow as tf

        param_eta = tf.placeholder(dtype=tf.float32, shape=[], name="param_eta")
        param_omega = tf.placeholder(dtype=tf.float32, shape=[], name="param_omega")
        old_entropy = tf.placeholder(dtype=tf.float32, shape=[], name="old_entropy")

        varphis = tf.placeholder(dtype=tf.float32, shape=[None, None], name="varphis")
        Kt = tf.placeholder(dtype=tf.float32, shape=[None, None], name="Kt")
        prec = tf.placeholder(dtype=tf.float32, shape=[None, None], name="prec")
        Waa = tf.placeholder(dtype=tf.float32, shape=[None, None], name="Waa")
        Wsa = tf.placeholder(dtype=tf.float32, shape=[None, None], name="Wsa")
        wa = tf.placeholder(dtype=tf.float32, shape=[None, None], name="wa")

# varphis = ext.new_tensor(
#             'varphis',
#             ndim=2,
