问题如下：
Under US GAAP, R&D is expensed for accounting report, but capitalized for tax purpose, the result is:
选项：
A.a deferred tax liability.
B.a deferred tax asset.
C.no deferred tax asset or liability.
解释：
Answer is B, under US GAAP, R&D must expenditure for accounting purpose, so accounting base is less than tax base, and the result is DTA.
我问下什么时候从 asset 去看 BS 公式什么时候从 liability 去看 BS 公式？
比如这个题
如果用讲义上的，就是从 asset 端去看， A.B. Asset = 0，T.B. Asset > 0，所以 A.B. - T.B.< 0 ，negative，是 DTA
如果从 liability 端去看，A.B. Liability >0, T.B. Liability = 0, 所以 (-A.B.) - (-T.B.) < 0, ,negative，出来的判定结果也是 DTA
所以是两种判断方式都可以么？
