import tensorflow as tf

result = tf.constant([0])
i = tf.constant(0)
c_1 = lambda i,result: tf.less(i, 10)
def b_1(i,result):

    j = tf.constant(0)
    c_2 = lambda i,j,res: tf.less(j, 10)
    result += 1
    def b_2(i, j,res):
        res += 1


        return i, tf.add(j, 1), res
    loop_2 = tf.while_loop(c_2, b_2, [i,j,result])


    return tf.add(i, 1), result
loop_1 = tf.while_loop(c_1, b_1, [i,result])

with tf.Session() as sess:
    print(sess.run(loop_1))