def lrelu1(x, a=0.2):
    with tf.name_scope("lrelu"):
        # adding these together creates the leak part and linear part
        # then cancels them out by subtracting/adding an absolute value term
        # leak: a*x/2 - a*abs(x)/2
        # linear: x/2 + abs(x)/2

        # this block looks like it has 2 inputs on the graph unless we do this
        x = tf.identity(x)
        return (0.5 * (1 + a)) * x + (0.5 * (1 - a)) * abs(x)

def lrelu2(x, a=0.2):
    with tf.name_scope("lrelu"):
        return tf.nn.relu(x) - a * tf.nn.relu(-x)