§ 2101.
(b)
Computation of tax
The tax imposed by this section shall be the amount equal to the excess (if any) of—
(1)
a tentative tax computed under section 2001(c) on the sum of—
(A)
the amount of the taxable estate, and
(B)
the amount of the adjusted taxable gifts, over
(2)
a tentative tax computed under section 2001(c) on the amount of the adjusted taxable gifts.
([Aug. 16, 1954, ch. 736], [68A Stat. 397]; [Pub. L. 89–809, title I, § 108(a)], Nov. 13, 1966, [80 Stat. 1571]; [Pub. L. 94–455, title XX, § 2001(c)(1)(D)], Oct. 4, 1976, [90 Stat. 1850]; [Pub. L. 100–647, title V, § 5032(a)], (c), Nov. 10, 1988, [102 Stat. 3669]; [Pub. L. 101–239, title VII, § 7815(c)], Dec. 19, 1989, [103 Stat. 2415]; [Pub. L. 103–66, title XIII, § 13208(b)(3)], Aug. 10, 1993, [107 Stat. 469]