import tensorflow as tf


        # specific to FeUdal
        self.prev_g = tf.placeholder(tf.float32, (None, None, self.g_dim))
        self.ri = tf.placeholder(tf.float32, (None,))
        self.s_diff = tf.placeholder(tf.float32, (None, self.g_dim))

    def build_perception(self):
        self._obs = tf.expand_dims(self.obs, -1)  # !
