16. PROPERTY AND DEPRECIATION

A summary of property and equipment at November 1, 2020 and November 3, 2019 in millions of dollars follows:

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*    Weighted-averages

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Total property and equipment additions in 2020, 2019, and 2018 were $815 million, $1,107 million, and $985 million and depreciation was $800 million, $779 million, and $754 million, respectively. Capitalized interest was $6 million, $7 million, and $4 million in the same periods, respectively. The cost of leased property and equipment under finance leases of $99 million and $62 million and accumulated depreciation of $36 million and $27 million at November 1, 2020 and November 3, 2019, respectively, is included in property and equipment.

Capitalized software has an estimated useful life of three years. The amounts of total capitalized software costs, including purchased and internally developed software, classified as “Other assets” at November 1, 2020 and November 3, 2019 were $1,339 million and $1,305 million, less accumulated amortization of $1,070 million and $1,023 million, respectively. Capitalized interest on software was $3 million and $5 million at November 1, 2020 and November 3, 2019, respectively. Amortization of these software costs in 2020, 2019, and 2018 was $133 million, $150 million, and $145 million, respectively.

The cost of compliance with foreseeable environmental requirements has been accrued and did not have a material effect on the company’s consolidated financial statements.