From c358955cef423a23bb899cb127c2d33514ee822f Mon Sep 17 00:00:00 2001
From: Yao Zhang <psyyz10@nottingham.ac.uk>
Date: Wed, 16 Aug 2017 17:12:24 +0800
Subject: [PATCH] Add abstract Operation, Add, Substract, Multiply and Divide
 operations (#1462)

* finsh Operation, Add, Substract, Multiply and Divide operations

* meet code review

* make acc not be supported

* meet code review

* make documentation better

* rename package object

* rename package object