import tensorflow as tf

        z = tf.matmul(x, wx) + tf.matmul(h, wh) + b
        i, f, o, u = tf.split(axis=1, num_or_size_splits=4, value=z)
        i = tf.nn.sigmoid(i)
        f = tf.nn.sigmoid(f)
        o = tf.nn.sigmoid(o)
        u = tf.tanh(u)
        c = f*c + i*u
        h = o*tf.tanh(c)
        xs[idx] = h
    s = tf.concat(axis=1, values=[c, h])
    return xs, s

def _ln(x, g, b, e=1e-5, axes=[1]):
    u, s = tf.nn.moments(x, axes=axes, keep_dims=True)
