two's complement

Noun

• The number obtained by complementing every bit of a given number and adding one. A number and its complement add to 2ⁿ, where n is the word size of the machine.
• The convention by which bit patterns with high bit 0 represent positive numbers from 0 to $2^\{n-1\}\; -\; 1$ directly, while bit patterns with high bit 1 represent negative numbers from -1 to $-2^\{n\; -\; 1\}$, n being the word size of the machine, and the numeric complement of a number is its two's complement.